public void editFunctionSignature(final FunctionDefinition functionDefinition) {
		DataTypeManager dataTypeManager = functionDefinition.getDataTypeManager();
		if (dataTypeManager == null) {
			throw new IllegalArgumentException("DataType " + functionDefinition.getPathName() +
				" has no DataTypeManager!  Make sure the " +
				"given DataType has been resolved by a DataTypeManager");
		}
		CategoryPath categoryPath = functionDefinition.getCategoryPath();
		Category category = dataTypeManager.getCategory(categoryPath);
		if (categoryPath == null) {
			throw new IllegalArgumentException(
				"DataType " + functionDefinition.getName() + " has no category path!");
		}
		editFunctionSignature(category, functionDefinition);
	}
Determines whether the indicated domain object can be closed. The user will be prompted
to save any editor changes. If the user cancels when prompted to save then the domain
object should not close.
@param dObj the domain object
@return true if it can close.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/editor/DataTypeEditorManager.java