class Sass::CanonicalizeContext

@see sass-lang.com/documentation/js-api/interfaces/canonicalizecontext/
Not all importers will need this information to resolve loads, but some may find it useful.
Contextual information passed to ‘canonicalize` and `find_file_url`.

def initialize(containing_url, from_import) 

def initialize(containing_url, from_import)
  @containing_url = containing_url
  @from_import = from_import
end