sequence.remove_work_calendar to remove related work times

Previously they were leaved orphaned

src/ifcopenshell-python/test/api/sequence/test_remove_work_calendar.py

@@ -0,0 +1,52 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import pytest
+import test.bootstrap
+import ifcopenshell.api
+import ifcopenshell.api.control
+import ifcopenshell.api.sequence
+
+
+# NOTE: sequence module features relies on entities introduced in IFC4
+# therefore no IFC2X3 tests
+class TestRemoveWorkCalendar(test.bootstrap.IFC4):
+    def test_remove_work_calendar(self):
+        self.file.create_entity("IfcProject")
+        work_calendar = ifcopenshell.api.sequence.add_work_calendar(self.file)
+
+        # Add work times.
+        ifcopenshell.api.sequence.add_work_time(self.file, work_calendar, "WorkingTimes")
+        ifcopenshell.api.sequence.add_work_time(self.file, work_calendar, "WorkingTimes")
+        ifcopenshell.api.sequence.add_work_time(self.file, work_calendar, "ExceptionTimes")
+        ifcopenshell.api.sequence.add_work_time(self.file, work_calendar, "ExceptionTimes")
+
+        # Assign tasks.
+        task = ifcopenshell.api.sequence.add_task(self.file)
+        ifcopenshell.api.control.assign_control(self.file, work_calendar, task)
+
+        ifcopenshell.api.sequence.remove_work_calendar(self.file, work_calendar)
+
+        assert len(self.file.by_type("IfcWorkCalendar")) == 0
+        assert len(self.file.by_type("IfcWorkTime")) == 0
+        assert len(self.file.by_type("IfcTask")) == 1
+        assert len(self.file.by_type("IfcRelAssignsToControl")) == 0
+
+
+class TestRemoveWorkCalendarIFC4X3(test.bootstrap.IFC4X3, TestRemoveWorkCalendar):
+    pass