anchor.diff:    Integer get negated => new Integer(-this._value);
     Integer minus(Integer other) => new Integer(this._value - other._value);
   
  -  Integer plus(Integer other) => new Integer(this._value + other._value);
  +  Integer plus([Integer other]) => new Integer(this._value + other._value);
   
     Integer power([Integer other]) => new Integer($dart$math.pow(this._value, other._value));
   
  
positive.code: abstract class Collection implements Iterable {}
  
  //
  // Correspondence.dart
  //
  
  
negative.code:   Integer get successor => new Integer(this._value + 1);
  
    // Comparable
    Comparison compare([Float other])
        =>  _value < other._value ? smaller : (_value > other._value ? larger : equal);
  
    //Comparison compare(Integer other);
  
  