code: public static AbstractMatrix getInstance(int rows, Object values, Class<?> cls)
      {
          int length = Array.getLength(values);
          if (length % rows != 0)
          {
              throw new IllegalArgumentException("not full rows");
          }
          return new AbstractMatrix(rows, copyOf(values, cls));
      }
docs: Returns new AbstractMatrix initialized to values.
  <p>E.g. 2x2 matrix has A00, A01, A10, A11
  @param rows Number of rows
  @param values Values row by row
  @return