def from=(location)
      if location then
        self.from_container = location.container
        self.from_row = location.row
        self.from_column = location.column
      end
      location
    end
def from=(location)
      if location then
        self.from_container = location.container
        self.from_row = location.row
        self.from_column = location.column
      end
      location
    end
Sets the from Location.