def Compile(self, filter_implementation):
    """Compile the expression."""
    arguments = [self.attribute]
    for argument in self.args:
      arguments.append(argument.Compile(filter_implementation))
    expander = filter_implementation.FILTERS['ValueExpander']
    context_cls = filter_implementation.FILTERS['Context']
    return context_cls(arguments=arguments,
                       value_expander=expander)
Compile the expression.