public StringExpression prepend(Expression<String> str) {
        return Expressions.stringOperation(Ops.CONCAT, str, mixin);
    }
Create a {@code concat(str, this)} expression

<p>Prepend the given String and return the result</p>

@param str string
@return str + this
querydsl-core/src/main/java/com/querydsl/core/types/dsl/StringExpression.java