How to Set the value of a cascading select list in an issue.

MutableIssue cIssue = (MutableIssue) transientVars.get("issue");
CustomField categoryCF = ComponentManager.getInstance().getCustomFieldManager().getCustomFieldObjectByName("Category");

if (categoryCF == null \|\| \!(categoryCF.getCustomFieldType() instanceof CascadingSelectCFType)) {
log.error("Expected customfield doesn't exist or doesn't have the expected type.");
}

// Obtain the FieldLayoutItem associated with the custom field for this issue
FieldLayoutItem fieldLayoutItem = null;
try {
fieldLayoutItem = ComponentManager.getInstance().getFieldLayoutManager().getFieldLayout(cIssue).getFieldLayoutItem(categoryCF);
} catch (FieldLayoutStorageException e) {
e.printStackTrace();
}

OptionsManager optionsManager = (OptionsManager)ComponentManager.getComponentInstanceOfType(OptionsManager.class);
// The current value of the cascadingselect of this issue.
Object cValue = categoryCF.getValue(cIssue);
CustomFieldParams newValues = new CustomFieldParamsImpl();
/\* Example how to put in an empty value for parent and child. Note that the parent option gets keyvalue "null" and child keyvalue "1".
\*/

newValues.put(null, null);
newValues.put("1", null);
ModifiedValue modifiedValue = new ModifiedValue(cValue, newValues);
categoryCF.updateValue(fieldLayoutItem, cIssue, modifiedValue, new DefaultIssueChangeHolder());

/\*
Example how to put in a certain value for parent and child. In this case, I already have the id of the options that I want to set.
\*/

// TODO: nullchecks for options.
// Get the corresponding parentoption object of the id.
Option parentOptionObj = optionsManager.findByOptionId(new Long(parentOption));
List parentOptionColl = new ArrayList();
parentOptionColl.add(parentOptionObj);
newValues.put(null, parentOptionColl);

Option childOptionObj = optionsManager.findByOptionId(new Long(childOption));
List childOptionColl = new ArrayList();
childOptionColl.add(childOptionObj);
newValues.put("1", childOptionColl);
ModifiedValue modifiedValue = new ModifiedValue(cValue, newValues);
categoryCF.updateValue(fieldLayoutItem, cIssue, modifiedValue, new DefaultIssueChangeHolder());

ManagerFactory.getCustomFieldManager().getCustomFieldObject(new Long(CASCADE_LIST_FIELD_ID));

private void updateCascadeValue(CustomField buildList, MutableIssue issue, String versionName, String buildValue, long cascadeListFieldId) {
 Options op = getOptions(cascadeListFieldId);
 CustomFieldParams newValues = new CustomFieldParamsImpl();
 Option parentOptionObj = op.getOptionForValue(versionName, null);
 List parentOptionColl = new ArrayList();
 parentOptionColl.add(parentOptionObj);
 newValues.put(null, parentOptionColl);
 Option childOptionObj = op.getOptionForValue(buildValue, parentOptionObj.getOptionId());
 List childOptionColl = new ArrayList();
 childOptionColl.add(childOptionObj);
 newValues.put("1", childOptionColl);
 Object oldValues = null;
 buildList.updateValue(null,
 issue, new ModifiedValue(issue.getCustomFieldValue(buildList), newValues),
 new DefaultIssueChangeHolder());
issue.store();
}