code: public static String arrayToPath(final String[] array) {
          if (array == null) {
              return "";
          }
  
          return Joiner.on(",").skipNulls().join(array);
      }
docs: Converts a String array to a String with coma separator
  example: String["a.soy", "b.soy"] - output: a.soy,b.soy
  @param array - array
  @return comma separated list