code: function ( path, base )
  { let filename
    let start = path.substr ( 0, 2 )
    if ( path.charAt ( 0 )  === '/' )
    { // absolute path
      filename = path
    }
    else if ( start == './' || start == '..' || path == '.' )
    { filename = lpath.resolve ( base, path )
    }
    else
    { // funky node_modules path not supported
      throw new Error
      ( `Cannot watch path '${ path }'  ( not a relative or absolute path ) ` )
    }
    return filename
  }
docs: Used by watch. Not full resolution.