code: def parse_selection_set(lexer: Lexer) -> SelectionSetNode:
      
      start = lexer.token
      return SelectionSetNode(
          selections=many_nodes(
              lexer, TokenKind.BRACE_L, parse_selection, TokenKind.BRACE_R
          ),
          loc=loc(lexer, start),
      )
docs: SelectionSet: {Selection+}