code: @Pure
  	public static double operator_power(Double a, Number b) {
  		return Math.pow(a, b.doubleValue());
  	}
docs: The <code>power</code> operator.
  
  @param a
  a double. May not be <code>null</code>.
  @param b
  a number. May not be <code>null</code>.
  @return <code>a ** b</code>
  @throws NullPointerException
  if {@code a} or {@code b} is <code>null</code>.