code: protected void validate(ST st, Set<String> expectedArguments){
  		Map<?,?> formalArgs = st.impl.formalArguments;
  		if(formalArgs==null){
  			for(String s : expectedArguments){
  				this.errors.addError("ST <{}> does not define argument <{}>", st.getName(), s);
  			}
  		}
  		else{
  			for(String s : expectedArguments){
  				if(!formalArgs.containsKey(s)){
  					this.errors.addError("ST <{}> does not define argument <{}>", st.getName(), s);
  				}
  			}
  		}
  	}
docs: Validates the ST object and marks all missing arguments.
  @param st ST object for validation
  @param expectedArguments expected arguments to test for