IFolder folder = ((IFolder)this.file.getParent());
String name = this.file.getName();
// Method File
String cexName = name.substring(0, name.lastIndexOf('.')) + ".cex";
IResource cexResource = folder.findMember(cexName);
if (cexResource != null){
this.implementationFile = (IFile)cexResource;
/*
* if we are working with a whole class file then
* we set the method file to the class file