Java – Manipulates output in a java8 stream

Suppose we have a list of 3 objects with values in the minute field as: 5, 5, 7, 8

int sumOfFields = found.stream()
        .filter(abc -> minutesLessThan5(abc.getMinutes())))
        .mapToInt(abc::getMinutes)
        .sum();

 will return 10

But how can I change my output
For example, instead of getMinutes, I want to return my own value, such as 40

int sumOfFields = found.stream()
        .filter(abc -> minutesLessThan5(abc.getMinutes())))
        .mapToInt(abc ->abc.getMinutes() = 40)  //this is pseudo code what I try to achive
        .sum();

 output should be 80.

Not quite sure why people aren’t answering this, but as noted in the comments, you can go either way

int sumOfFields = found.stream()
        .filter(abc -> minutesLessThan5(abc.getMinutes())))
        .mapToInt(abc -> 40) // map value to be returned as 40 
        .sum();

Or since you want to replace all such values with a constant value of 40, you can also use count() and multiply it by the constant value.

int sumOfFields = (int) found.stream() // casting from long to int
        .filter(abc -> minutesLessThan5(abc.getMinutes())))
        .count() * 40;