@Nonnull
    public static String trimToEmpty(@Nullable String str) {
        if (str == null) {
            return "";
        } else {
            return str.trim();
        }
    }
@Nonnull
    public static String trimToEmpty(@Nullable String str) {
        if (str == null) {
            return "";
        } else {
            return str.trim();
        }
    }
@ Nonnull public static String trimToEmpty ( @ Nullable String str ) { if ( str == null ) { return "" ; } else { return str . trim ( ) ; } }
if the given string is {@code null}, return {@code ""}, else return {@link String#trim()}.

@param str the string to trim
@return the trimmed string
if the given string is { @code null } return { @code } else return { @link String#trim () } .