Then we define a class that implements that interface:

      // Constructor template for UTC1:
      //     new UTC1 (h, m)
      // Interpretation:
      //     h is the hour (between 0 and 23, inclusive)
      //     m is the minute (between 0 and 59, inclusive)
      
      class UTC1 implements UTC {
      
          int h;    // the hour, limited to [0,23]
          int m;    // the minute, limited to [0,59]
      
          // the Java constructor
      
          UTC1 (int h, int m) {
              this.h = h;
              this.m = m;
          }
      
          // public methods
      
          // Returns the hour, between 0 and 23 inclusive.
      
          public int hour () { return h; }
      
          // Returns the minute, between 0 and 59 inclusive.
      
          public int minute () { return m; }
      
          // Returns true iff the given UTC is equal to this UTC.
      
          public boolean isEqual (UTC t2) {
              return (h == t2.hour()) && (m == t2.minute());
          }
      
          ...
      }