public NumberExpression<Integer> indexOf(Expression<String> str, int i) {
        return Expressions.numberOperation(Integer.class, Ops.INDEX_OF_2ARGS, mixin, str, ConstantImpl.create(i));
    }
Create a {@code this.indexOf(str)} expression

<p>Get the index of the given substring in this String, starting from the given index</p>

@param str string
@param i zero based index
@return this.indexOf(str)
querydsl-core/src/main/java/com/querydsl/core/types/dsl/StringExpression.java