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    "
        EXPR_STMT
          BIN_EXPR
            UNDERSCORE_EXPR
              UNDERSCORE "_"
            WHITESPACE " "
            EQ "="
            WHITESPACE " "
            LITERAL
              INT_NUMBER "1"
          SEMICOLON ";"
        WHITESPACE "\n    "
        EXPR_STMT
          BIN_EXPR
            CALL_EXPR
              PATH_EXPR
                PATH
                  PATH_SEGMENT
                    NAME_REF
                      IDENT "Some"
              ARG_LIST
                L_PAREN "("
                UNDERSCORE_EXPR
                  UNDERSCORE "_"
                R_PAREN ")"
            WHITESPACE " "
            EQ "="
            WHITESPACE " "
            PATH_EXPR
              PATH
                PATH_SEGMENT
                  NAME_REF
                    IDENT "None"
          SEMICOLON ";"
        WHITESPACE "\n"
        R_CURLY "}"
  WHITESPACE "\n"
