Eclipse show error marker "The method execute(IFile, StructuredModelWrapper.ICommand) is ambiguous for the type StructuredModelWrapper". On the call

StructuredModelWrapper.execute(testFile, xmlDocument -> assertNotNull(xmlDocument));

There are 2 execute methods, with similar interfaces. Though compiler shoud resolve the method by assertNotNull having 'void' for the return type, and tycho build currently finds no problem with it, still this code looks on the verge of fault and better be improved by changing it to

StructuredModelWrapper.execute(testFile, xmlDocument -> { assertNotNull(xmlDocument); });