docs: function createPatternFilter(ignoreFile) {
      return function (pattern) {
          var patternVariations = createPatternVariations(pattern);
  
          // Loop through patterns in .npmignore and try to find duplicates
          var duplicates = patternVariations.filter(function (patternVar) {
              return ignoreFile.patterns.indexOf(patternVar) !== -1;
          });
  
          return !duplicates.length;
      };
  }