Finds a given type name in the current scope.

    Args:
      package: The package the proto should be located in.
      type_name: The name of the type to be found in the scope.
      scope: Dict mapping short and full symbols to message and enum types.

    Returns:
      The descriptor for the requested type.

def _GetTypeFromScope(self, package, type_name, scope):
    """Finds a given type name in the current scope.

    Args:
      package: The package the proto should be located in.
      type_name: The name of the type to be found in the scope.
      scope: Dict mapping short and full symbols to message and enum types.

    Returns:
      The descriptor for the requested type.
    """
    if type_name not in scope:
      components = _PrefixWithDot(package).split('.')
      while components:
        possible_match = '.'.join(components + [type_name])
        if possible_match in scope:
          type_name = possible_match
          break
        else:
          components.pop(-1)
    return scope[type_name]