code: public static String detectSourceType(Element element, String adapterClazz) {
  		TypeElement a = BaseProcessor.elementUtils.getTypeElement(adapterClazz);
  		for (Element i : BaseProcessor.elementUtils.getAllMembers(a)) {
  			if (i.getKind() == ElementKind.METHOD && "toJava".equals(i.getSimpleName().toString())) {
  				ExecutableElement method = (ExecutableElement) i;
  				return TypeUtility.typeName(method.getReturnType()).toString();
  			}
  		}
  
  		AssertKripton.fail("In '%s', class '%s' can not be used as type adapter", element, adapterClazz);
  		return null;
  	}
docs: Detect source type.
  
  @param element the element
  @param adapterClazz the adapter clazz
  @return the string