code: @Throws(IllegalPositiveArgumentException.class)
  	public static double notPositive(final double value, @Nullable final String name) {
  		if (value > 0.0) {
  			throw new IllegalPositiveArgumentException(name, value);
  		}
  		return value;
  	}
docs: Ensures that an double reference passed as a parameter to the calling method is not greater than {@code 0}.
  
  @param value
  a number
  @param name
  name of the number reference (in source code)
  @return the non-null reference that was validated
  @throws IllegalNullArgumentException
  if the given argument {@code reference} is smaller than {@code 0}