(p)
union : seen_union '{' field_seq '}'
union : seen_union '{' field_seq '}'
union : seen_union { field_seq }
def p_union(p):
    '''union : seen_union '{' field_seq '}' '''
    val = _fill_in_struct(p[1], p[3])
    _add_thrift_meta('unions', val)
def p_union ( p ) : val = _fill_in_struct ( p [ 1 ] , p [ 3 ] ) _add_thrift_meta ( 'unions' , val )