code: def find_piece(self, piece):
          
          for i, _ in enumerate(self.position):
              for j, _ in enumerate(self.position):
                  loc = Location(i, j)
  
                  if not self.is_square_empty(loc) and \
                          self.piece_at_square(loc) == piece:
                      return loc
  
          raise ValueError("{} \nPiece not found: {}".format(self, piece))
docs: Finds Location of the first piece that matches piece.
          If none is found, Exception is raised.
  
          :type: piece: Piece
          :rtype: Location