def populate_classified_values(
            self, unassigned_values, assigned_values, default_classes):
        """Populate lstUniqueValues and treeClasses.from the parameters.

        :param unassigned_values: List of values that haven't been assigned
            to a class. It will be put in self.lstUniqueValues.
        :type unassigned_values: list

        :param assigned_values: Dictionary with class as the key and list of
            value as the value of the dictionary. It will be put in
            self.treeClasses.
        :type assigned_values: dict

        :param default_classes: Default classes from unit.
        :type default_classes: list
        """
        # Populate the unique values list
        self.lstUniqueValues.clear()
        self.lstUniqueValues.setSelectionMode(
            QAbstractItemView.ExtendedSelection)
        for value in unassigned_values:
            value_as_string = value is not None and str(value) or 'NULL'
            list_item = QListWidgetItem(self.lstUniqueValues)
            list_item.setFlags(
                Qt.ItemIsEnabled
                | Qt.ItemIsSelectable
                | Qt.ItemIsDragEnabled)
            list_item.setData(Qt.UserRole, value)
            list_item.setText(value_as_string)
            self.lstUniqueValues.addItem(list_item)
        # Populate assigned values tree
        self.treeClasses.clear()
        self.treeClasses.invisibleRootItem().setFlags(Qt.ItemIsEnabled)
        for default_class in default_classes:
            # Create branch for class
            tree_branch = QTreeWidgetItem(self.treeClasses)
            tree_branch.setFlags(Qt.ItemIsDropEnabled | Qt.ItemIsEnabled)
            tree_branch.setExpanded(True)
            tree_branch.setFont(0, bold_font)
            if 'name' in default_class:
                default_class_name = default_class['name']
            else:
                default_class_name = default_class['key']
            tree_branch.setText(0, default_class_name)
            tree_branch.setData(0, Qt.UserRole, default_class['key'])
            if 'description' in default_class:
                tree_branch.setToolTip(0, default_class['description'])
            # Assign known values
            for value in assigned_values[default_class['key']]:
                string_value = value is not None and str(value) or 'NULL'
                tree_leaf = QTreeWidgetItem(tree_branch)
                tree_leaf.setFlags(
                    Qt.ItemIsEnabled
                    | Qt.ItemIsSelectable
                    | Qt.ItemIsDragEnabled)
                tree_leaf.setData(0, Qt.UserRole, value)
                tree_leaf.setText(0, string_value)
Populate lstUniqueValues and treeClasses.from the parameters.

        :param unassigned_values: List of values that haven't been assigned
            to a class. It will be put in self.lstUniqueValues.
        :type unassigned_values: list

        :param assigned_values: Dictionary with class as the key and list of
            value as the value of the dictionary. It will be put in
            self.treeClasses.
        :type assigned_values: dict

        :param default_classes: Default classes from unit.
        :type default_classes: list