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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_coord_line_number(self,coord):
 """return the one-indexed line number given the coordinates"""

    if coord[0] in self._coords:
      if coord[1] in self._coords[coord[0]]:
        return self._coords[coord[0]][coord[1]]
    return None