def METHOD_NAME(self, index: QtCore.QModelIndex, role=QtCore.Qt.DisplayRole):
    """Required by Qt."""
    if not index.isValid():
        return None
    idx = index.row()
    prop = self._props[index.column()]
    if idx >= self.rowCount():
        return None
    if role == QtCore.Qt.DisplayRole:
        if prop == "filename":
            return self.filenames[idx]
    elif role == QtCore.Qt.ForegroundRole:
        return QtGui.QColor("red") if self.missing[idx] else None
    return None