Returns a column from its name.
        Input
        -----
        name : columnAlias of the column to retrieve
        
        Return
        ------
        A Column object or None when the name cannot be found.

def getColumnByColumnAlias(self, name):
        """Returns a column from its name.
        Input
        -----
        name : columnAlias of the column to retrieve
        
        Return
        ------
        A Column object or None when the name cannot be found.        
        """
        result = None
        for column in self.__columns:
            columnAlias = column.getColumnAlias()
            if columnAlias == name:
                result = column
                break
        return result