private static int trimBegin( String str, int beginIndex, int endIndex ) {
		// skip leading whitespace
		while( beginIndex < endIndex && str.charAt( beginIndex ) <= ' ' )
			beginIndex++;
		return beginIndex;
	}
This is equal to {@code str.trim().isEmpty()},
but avoids temporary trimmed substring allocation.

@since 2
flatlaf-core/src/main/java/com/formdev/flatlaf/util/StringUtils.java