def __parameter_default(self, field):
if field.default:<EOL><INDENT>if isinstance(field, messages.EnumField):<EOL><INDENT>return field.default.name<EOL><DEDENT>else:<EOL><INDENT>return field.default<EOL><DEDENT><DEDENT>
Returns default value of field if it has one.

        Args:
          field: A simple field.

        Returns:
          The default value of the field, if any exists, with the exception of an
              enum field, which will have its value cast to a string.