operator == method
- @override
 
The equality operator.
The default behavior for all Objects is to return true if and
only if this and other are the same object.
Override this method to specify a different equality relation on a class. The overriding method must still be an equivalence relation. That is, it must be:
- 
Total: It must return a boolean for all arguments. It should never throw or return
null. - 
Reflexive: For all objects
o,o == omust be true. - 
Symmetric: For all objects
o1ando2,o1 == o2ando2 == o1must either both be true, or both be false. - 
Transitive: For all objects
o1,o2, ando3, ifo1 == o2ando2 == o3are true, theno1 == o3must be true. 
The method should also be consistent over time, so whether two objects are equal should only change if at least one of the objects was modified.
If a subclass overrides the equality operator it should override the hashCode method as well to maintain consistency.
Implementation
@override
bool operator ==(dynamic other) {
  if (identical(this, other))
    return true;
  if (other.runtimeType != runtimeType)
    return false;
  final TextTheme typedOther = other;
  return display4 == typedOther.display4
      && display3 == typedOther.display3
      && display2 == typedOther.display2
      && display1 == typedOther.display1
      && headline == typedOther.headline
      && title == typedOther.title
      && subhead == typedOther.subhead
      && body2 == typedOther.body2
      && body1 == typedOther.body1
      && caption == typedOther.caption
      && button == typedOther.button
      && subtitle == typedOther.subtitle
      && overline == typedOther.overline;
}