code: public NumberExpression<Integer> locate(Expression<String> str) {
          return Expressions.numberOperation(Integer.class, Ops.StringOps.LOCATE, str, mixin);
      }
docs: Create a {@code locate(str, this)} expression
  
  <p>Get the position of the given String in this String, the first position is 1</p>
  
  @param str string
  @return locate(str, this)