Avoid setters without gettersDRT-W1068

DON'T define a setter without a corresponding getter.

Defining a setter without defining a corresponding getter can lead to logical inconsistencies. Doing this could allow you to set a property to some value, but then upon observing the property's value, it could easily be different.

BAD:

class Bad {
  int l, r;

  set length(int newLength) {
    r = l + newLength;
  }
}

GOOD:

class Good {
  int l, r;

  int get length => r - l;

  set length(int newLength) {
    r = l + newLength;
  }
}