code: public boolean every(Func1<? super T, Boolean> predicate) {
          for (T item : this) {
              if (!predicate.call(item))
                  return false;
          }
          return true;
      }
docs: Returns true if all of stream items satisfy a given condition.
  
  @param predicate a condition to test.
  @return true if all of stream items satisfy a given condition.