SOURCE_FILE
  FN
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "foo"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        WHITESPACE "\n   "
        FOR_EXPR
          FOR_KW "for"
          WHITESPACE " "
          IDENT_PAT
            NAME
              IDENT "_x"
          WHITESPACE " "
          IN_KW "in"
          WHITESPACE " "
          RANGE_EXPR
            LITERAL
              INT_NUMBER "0"
            WHITESPACE " "
            DOT2 ".."
            WHITESPACE " "
            METHOD_CALL_EXPR
              PAREN_EXPR
                L_PAREN "("
                RANGE_EXPR
                  LITERAL
                    INT_NUMBER "0"
                  WHITESPACE " "
                  DOT2 ".."
                  WHITESPACE " "
                  BLOCK_EXPR
                    STMT_LIST
                      L_CURLY "{"
                      BIN_EXPR
                        LITERAL
                          INT_NUMBER "1"
                        WHITESPACE " "
                        PLUS "+"
                        WHITESPACE " "
                        LITERAL
                          INT_NUMBER "2"
                      R_CURLY "}"
                R_PAREN ")"
              DOT "."
              NAME_REF
                IDENT "sum"
              GENERIC_ARG_LIST
                COLON2 "::"
                L_ANGLE "<"
                TYPE_ARG
                  PATH_TYPE
                    PATH
                      PATH_SEGMENT
                        NAME_REF
                          IDENT "u32"
                R_ANGLE ">"
              ARG_LIST
                L_PAREN "("
                R_PAREN ")"
          WHITESPACE " "
          BLOCK_EXPR
            STMT_LIST
              L_CURLY "{"
              WHITESPACE "\n       "
              EXPR_STMT
                BREAK_EXPR
                  BREAK_KW "break"
                SEMICOLON ";"
              WHITESPACE "\n   "
              R_CURLY "}"
        WHITESPACE "\n"
        R_CURLY "}"
  WHITESPACE "\n"