anchor.diff:    /** Returns `this`. */
     int floor();
   
  -  /** Returns [this]. */
  +  /** Returns `this`. */
     int ceil();
   
  -  /** Returns [this]. */
  +  /** Returns `this`. */
     int truncate();
   
     /** Returns `this.toDouble()`. */
  
positive.code:   double truncateToDouble();
  
    /**
     * Returns a representation of this [int] value.
     *
     * It should always be the case that if [:i:] is an [int] value,
     * then [:i == int.parse(i.toString()):].
     */
    String toString();
  
  
negative.code:   /** Returns true if and only if this integer is odd. */
    bool get isOdd;
  
    /**
     * Return the negative value of this integer.
     *
     * The result of negating an integer always has the opposite sign, except
     * for zero, which is its own negation.
     */
    int operator -();
  
    /**
     * Returns the absolute value of this integer.
     *
     * For any integer `x`, the result is the same as `x < 0 ? -x : x`.
     */
    int abs();
  
    /** Returns `this`. */
  