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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 addColumn(self, columnName, dtype, defaultValue):
 """Adds a column with the given parameters to the underlying model This method is also a slot. If no model is set, nothing happens. Args: columnName (str):
 The name of the new column. dtype (numpy.dtype):
 The datatype of the new column. defaultValue (object):
 Fill the column with this value. """

        model = self.tableView.model()

        if model is not None:
            model.addDataFrameColumn(columnName, dtype, defaultValue)

        self.addColumnButton.setChecked(False)