code: public boolean is(MatrixPredicate predicate) {
          MatrixIterator it = iterator();
          boolean result = predicate.test(rows, columns);
  
          while (it.hasNext() && result) {
              double x = it.next();
              int i = it.rowIndex();
              int j = it.columnIndex();
              result = predicate.test(i, j, x);
          }
  
          return result;
      }
docs: Checks whether this matrix compiles with given {@code predicate} or not.
  
  @param predicate the matrix predicate
  
  @return whether this matrix compiles with predicate