Return True if the input TypedField `field` contains instance attributes
    that match the input parameters.

    Args:
        field: A TypedField instance.
        params: A dictionary of TypedField instance attribute-to-value mappings.

    Returns:
        True if the input TypedField matches the input parameters.

def _matches(field, params):
    """Return True if the input TypedField `field` contains instance attributes
    that match the input parameters.

    Args:
        field: A TypedField instance.
        params: A dictionary of TypedField instance attribute-to-value mappings.

    Returns:
        True if the input TypedField matches the input parameters.
    """
    fieldattrs = six.iteritems(params)
    return all(getattr(field, attr) == val for attr, val in fieldattrs)