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//! Conditional processing attributes: `requiredExtensions`, `requiredFeatures`, `systemLanguage`.
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#[allow(unused_imports, deprecated)]
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use std::ascii::AsciiExt;
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use std::str::FromStr;
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use language_tags::LanguageTag;
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use crate::accept_language::{LanguageTags, UserLanguage};
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use crate::error::*;
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use crate::rsvg_log;
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use crate::session::Session;
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// No extensions at the moment.
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static IMPLEMENTED_EXTENSIONS: &[&str] = &[];
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#[derive(Debug, PartialEq)]
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pub struct RequiredExtensions(pub bool);
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impl RequiredExtensions {
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    /// Parse a requiredExtensions attribute.
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    ///
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    /// <http://www.w3.org/TR/SVG/struct.html#RequiredExtensionsAttribute>
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    pub fn from_attribute(s: &str) -> RequiredExtensions {
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        RequiredExtensions(
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            s.split_whitespace()
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                .all(|f| IMPLEMENTED_EXTENSIONS.binary_search(&f).is_ok()),
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        )
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    }
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    /// Evaluate a requiredExtensions value for conditional processing.
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    pub fn eval(&self) -> bool {
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        self.0
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    }
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}
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// Keep these sorted alphabetically for binary_search.
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static IMPLEMENTED_FEATURES: &[&str] = &[
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    "http://www.w3.org/TR/SVG11/feature#BasicFilter",
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    "http://www.w3.org/TR/SVG11/feature#BasicGraphicsAttribute",
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    "http://www.w3.org/TR/SVG11/feature#BasicPaintAttribute",
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    "http://www.w3.org/TR/SVG11/feature#BasicStructure",
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    "http://www.w3.org/TR/SVG11/feature#BasicText",
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    "http://www.w3.org/TR/SVG11/feature#ConditionalProcessing",
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    "http://www.w3.org/TR/SVG11/feature#ContainerAttribute",
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    "http://www.w3.org/TR/SVG11/feature#Filter",
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    "http://www.w3.org/TR/SVG11/feature#Gradient",
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    "http://www.w3.org/TR/SVG11/feature#Image",
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    "http://www.w3.org/TR/SVG11/feature#Marker",
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    "http://www.w3.org/TR/SVG11/feature#Mask",
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    "http://www.w3.org/TR/SVG11/feature#OpacityAttribute",
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    "http://www.w3.org/TR/SVG11/feature#Pattern",
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    "http://www.w3.org/TR/SVG11/feature#SVG",
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    "http://www.w3.org/TR/SVG11/feature#SVG-static",
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    "http://www.w3.org/TR/SVG11/feature#Shape",
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    "http://www.w3.org/TR/SVG11/feature#Structure",
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    "http://www.w3.org/TR/SVG11/feature#Style",
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    "http://www.w3.org/TR/SVG11/feature#View",
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    "org.w3c.svg.static", // deprecated SVG 1.0 feature string
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];
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#[derive(Debug, PartialEq)]
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pub struct RequiredFeatures(pub bool);
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impl RequiredFeatures {
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    // Parse a requiredFeatures attribute
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    // http://www.w3.org/TR/SVG/struct.html#RequiredFeaturesAttribute
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    pub fn from_attribute(s: &str) -> RequiredFeatures {
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        RequiredFeatures(
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            s.split_whitespace()
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                .all(|f| IMPLEMENTED_FEATURES.binary_search(&f).is_ok()),
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        )
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    }
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    /// Evaluate a requiredFeatures value for conditional processing.
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    pub fn eval(&self) -> bool {
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        self.0
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    }
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}
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/// The systemLanguage attribute inside `<cond>` element's children.
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///
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/// Parsing the value of a `systemLanguage` attribute may fail if the document supplies
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/// invalid BCP47 language tags.  In that case, we store an `Invalid` variant.
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///
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/// That variant is used later, during [`SystemLanguage::eval`], to see whether the
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/// `<cond>` should match or not.
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#[derive(Debug, PartialEq)]
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pub enum SystemLanguage {
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    Valid(LanguageTags),
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    Invalid,
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}
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impl SystemLanguage {
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    /// Parse a `systemLanguage` attribute and match it against a given `Locale`
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    ///
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    /// The [`systemLanguage`] conditional attribute is a
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    /// comma-separated list of [BCP47] Language Tags.  This function
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    /// parses the attribute and matches the result against a given
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    /// `locale`.  If there is a match, i.e. if the given locale
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    /// supports one of the languages listed in the `systemLanguage`
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    /// attribute, then the `SystemLanguage.0` will be `true`;
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    /// otherwise it will be `false`.
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    ///
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    /// Normally, calling code will pass `&Locale::current()` for the
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    /// `locale` attribute; this is the user's current locale.
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    ///
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    /// [`systemLanguage`]: https://www.w3.org/TR/SVG/struct.html#ConditionalProcessingSystemLanguageAttribute
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    /// [BCP47]: http://www.ietf.org/rfc/bcp/bcp47.txt
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    pub fn from_attribute(s: &str, session: &Session) -> SystemLanguage {
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        let attribute_tags = s
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            .split(',')
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            .map(str::trim)
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            .map(|s| {
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                LanguageTag::from_str(s).map_err(|e| {
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                    ValueErrorKind::parse_error(&format!("invalid language tag \"{s}\": {e}"))
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                })
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            })
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            .collect::<Result<Vec<LanguageTag>, _>>();
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        match attribute_tags {
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            Ok(tags) => SystemLanguage::Valid(LanguageTags::from(tags)),
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            Err(e) => {
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                rsvg_log!(
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                    session,
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                    "ignoring systemLanguage attribute with invalid value: {}",
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                    e
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                );
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                SystemLanguage::Invalid
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            }
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        }
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    }
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    /// Evaluate a systemLanguage value for conditional processing.
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    pub fn eval(&self, user_language: &UserLanguage) -> bool {
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        match *self {
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            SystemLanguage::Valid(ref tags) => user_language.any_matches(tags),
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            SystemLanguage::Invalid => false,
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        }
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    }
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}
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#[cfg(test)]
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mod tests {
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    use super::*;
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    use locale_config::Locale;
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    #[test]
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    fn required_extensions() {
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        assert_eq!(
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            RequiredExtensions::from_attribute("http://test.org/NotExisting/1.0"),
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            RequiredExtensions(false)
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        );
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    }
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    #[test]
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    fn required_features() {
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        assert_eq!(
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            RequiredFeatures::from_attribute("http://www.w3.org/TR/SVG11/feature#NotExisting"),
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            RequiredFeatures(false)
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        );
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        assert_eq!(
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            RequiredFeatures::from_attribute("http://www.w3.org/TR/SVG11/feature#BasicFilter"),
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            RequiredFeatures(true)
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        );
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        assert_eq!(
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            RequiredFeatures::from_attribute(
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                "http://www.w3.org/TR/SVG11/feature#BasicFilter \
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                 http://www.w3.org/TR/SVG11/feature#NotExisting",
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            ),
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            RequiredFeatures(false)
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        );
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        assert_eq!(
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            RequiredFeatures::from_attribute(
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                "http://www.w3.org/TR/SVG11/feature#BasicFilter \
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                 http://www.w3.org/TR/SVG11/feature#BasicText",
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            ),
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            RequiredFeatures(true)
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        );
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    }
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    #[test]
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    fn system_language() {
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        let session = Session::new_for_test_suite();
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        let locale = Locale::new("de,en-US").unwrap();
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        let user_language = UserLanguage::LanguageTags(LanguageTags::from_locale(&locale).unwrap());
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        assert!(matches!(
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            SystemLanguage::from_attribute("", &session),
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            SystemLanguage::Invalid
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        ));
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        assert!(matches!(
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            SystemLanguage::from_attribute("12345", &session),
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            SystemLanguage::Invalid
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        ));
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        assert!(!SystemLanguage::from_attribute("fr", &session).eval(&user_language));
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        assert!(!SystemLanguage::from_attribute("en", &session).eval(&user_language));
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        assert!(SystemLanguage::from_attribute("de", &session).eval(&user_language));
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        assert!(SystemLanguage::from_attribute("en-US", &session).eval(&user_language));
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        assert!(!SystemLanguage::from_attribute("en-GB", &session).eval(&user_language));
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        assert!(SystemLanguage::from_attribute("DE", &session).eval(&user_language));
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        assert!(SystemLanguage::from_attribute("de-LU", &session).eval(&user_language));
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        assert!(SystemLanguage::from_attribute("fr, de", &session).eval(&user_language));
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    }
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}