code: public static ImmutableMatrix3 copy(Matrix3 source) {
  		if (source instanceof ImmutableMatrix3) return (ImmutableMatrix3)source;
  		return new ImmutableMatrix3(source);
  	}
docs: Returns an immutable matrix with the same values as the argument.
  
  @param source the matrix containing the data for the new immutable matrix
  @return an immutable matrix containing the same elements as {@code source}
  @throws NullPointerException if {@code source} is {@code null}