code: protected boolean sourceSignatureChanged(String tName, Compiler compiler)
          throws IOException {
  
          TemplateRepository tRepo = TemplateRepository.getInstance();
          TemplateInfo templateInfo = tRepo.getTemplateInfo(tName);
          if(null == templateInfo) {
              return false;
          }
  
          CompilationUnit unit = compiler.getCompilationUnit(tName, null);
          if (unit == null) {
              return false;
          }
          
          return ! unit.signatureEquals(tName, templateInfo.getParameterTypes(), templateInfo.getReturnType());
      }
docs: parses the tea source file and compares the signature to the signature of the current class file
  in the TemplateRepository
  
  @return true if tea source signature is different than the class file signature or class file does not exist