public static String toCamelCase(String str) {
        return toCamelCase(str, false, '_', '-', ' ');
    }
<p>Converts all words separated by " ", "-", and "_" to CamelCase.

<p>The first character is always converted to lowercase.</p>

@param str the String to be converted to camelCase, may be null
@return camelCase of String, <code>null</code> if null String input
smithy-utils/src/main/java/software/amazon/smithy/utils/CaseUtils.java