code: function file( path, content ) {
      try {
          if ( typeof content === 'undefined' ) {
              if ( !FS.existsSync( path ) ) return null;
              return FS.readFileSync( path );
          }
          const dir = Path.dirname( path );
          mkdir( dir );
          FS.writeFileSync( path, content );
          return content;
      } catch ( ex ) {
          console.warn( "content:", content );
          throw new Error( `${ex}\n...in pathutils/file("${path}", ${typeof content})` );
      }
  }
docs: Read or write the content of a file.
  
  If  `content` is  undefined, the  content  is read,  otherwise it  is
  written.
  If the  file to be  written is in  a non-existent subfolder,  the whole
  path will be created with the `mkdir`function.
  
  @param {string} path - Path of the file to read or write.
  @param {string} content - Optional. If omitted, we return the content of the file.
  Otherwise, we save this content to the file.
  @returns {string} The file content.