@Override
    public int length() {
        return str.length();
    }
Formats an sql statement from multiple tokens.<br>
Leading and trailing whitespace is removed from each token and empty tokens ignored.<br>
The tokens are joined using a single blank character to create the sql string.<br>
Finally, any trailing semicolons are removed from the resulting sql.

@param tokens collection of tokens
@return formatted sql string
core/src/main/java/org/jdbi/v3/core/Sql.java