==================
label command
==================

foo:
  LABEL foo=bar \
      simple_quoted='a b c d' \
      double_quoted="great stuff!"

---

    (source_file
      (target
        name: (identifier)
        (block
          (label_command
            (label
              label: (identifier)
              value: (string
                (unquoted_string)))
            (line_continuation)
            (label
              label: (identifier)
              value: (string
                (single_quoted_string)))
            (line_continuation)
            (label
              label: (identifier)
              value: (string
                (double_quoted_string)))))))

