public static CharSeq of(final CharSequence pattern) {
		return new CharSeq(expand(pattern));
	}
Expands the character range for the given {@code pattern}. E.g.
{@code a-zA-Z0-1} will return a string containing all upper and lower
case characters (from a to z), and all digits form 0 to 9.

@see #expand(CharSequence)

@param pattern the {@code pattern} to expand.
@return the expanded pattern.
@throws PatternSyntaxException if the pattern could not be expanded.
@throws NullPointerException if the pattern is {@code null}.
jenetics/src/main/java/io/jenetics/util/CharSeq.java