Function valid::invalid_relation

pub fn invalid_relation(
    code: impl Into<Cow<'static, str>>, 
    field_name1: impl Into<Cow<'static, str>>, 
    field_value1: impl Into<Value>, 
    field_name2: impl Into<Cow<'static, str>>, 
    field_value2: impl Into<Value>
) -> ConstraintViolation

Convenience function to construct a ConstraintViolation for a validation performed in the RelatedFields context.