code: public static CharacterChromosome of(
  		final CharSeq validCharacters,
  		final int length
  	) {
  		return of(validCharacters, IntRange.of(length));
  	}
docs: Create a new chromosome with the {@code validCharacters} char set as
  valid characters.
  
  @since 4.3
  
  @param validCharacters the valid characters for this chromosome.
  @param length the {@code length} of the new chromosome.
  @return a new {@code CharacterChromosome} with the given parameter
  @throws NullPointerException if the {@code validCharacters} is
  {@code null}.
  @throws IllegalArgumentException if the length of the gene sequence is
  empty, doesn't match with the allowed length range, the minimum
  or maximum of the range is smaller or equal zero or the given
  range size is zero.