def METHOD_NAME(self, row, count, parent=QModelIndex()):
    """
    Inserts new time period - value pairs into the pattern.
    New time periods are initialized to empty strings and the corresponding values to zeros.
    Args:
        row (int): an index where to insert the new data
        count (int): number of time period - value pairs to insert
        parent (QModelIndex): an index to a parent model
    Returns:
        bool: True if the operation was successful
    """
    self.beginInsertRows(parent, row, row + count - 1)
    old_indexes = self._value.indexes
    old_values = self._value.values
    new_indexes = list(old_indexes)
    for _ in range(count):
        new_indexes.insert(row, "")
    if row == len(old_values):
        new_values = np.append(old_values, np.zeros(count))
    else:
        new_values = np.insert(old_values, row, np.zeros(count))
    self._value = TimePattern(new_indexes, new_values)
    self.endInsertRows()
    return True