parameters: (self, p)
docstring: expression : LPAREN expression RPAREN
docstring_summary: expression : LPAREN expression RPAREN
docstring_tokens: expression : LPAREN expression RPAREN
function: def p_expression_group(self, p):
          'expression : LPAREN expression RPAREN'
          p[0] = p[2]
function_tokens: def p_expression_group ( self , p ) : p [ 0 ] = p [ 2 ]