javagit/src/main/java/edu/nyu/cs/javagit/utilities/CheckUtilities.java
public static void checkNullListArgument(List<?> list, String variableName) {
    // TODO (jhl388): Write a unit test for this method.
    if (null == list) {
      throw new NullPointerException(ExceptionMessageMap.getMessage("000005")
          + "  { variableName=[" + variableName + "] }");
    }
    if (list.size() == 0) {
      throw new IllegalArgumentException(ExceptionMessageMap.getMessage("000005")
          + "  { variableName=[" + variableName + "] }");
    }
    for (int i = 0; i < list.size(); i++) {
      checkNullArgument(list.get(i), variableName);
    }
  }
public static void checkNullListArgument(List<?> list, String variableName) {
    // TODO (jhl388): Write a unit test for this method.
    if (null == list) {
      throw new NullPointerException(ExceptionMessageMap.getMessage("000005")
          + "  { variableName=[" + variableName + "] }");
    }
    if (list.size() == 0) {
      throw new IllegalArgumentException(ExceptionMessageMap.getMessage("000005")
          + "  { variableName=[" + variableName + "] }");
    }
    for (int i = 0; i < list.size(); i++) {
      checkNullArgument(list.get(i), variableName);
    }
  }
public static void checkNullListArgument ( List < ? > list , String variableName ) { // TODO (jhl388): Write a unit test for this method. if ( null == list ) { throw new NullPointerException ( ExceptionMessageMap . getMessage ( "000005" ) + "  { variableName=[" + variableName + "] }" ) ; } if ( list . size ( ) == 0 ) { throw new IllegalArgumentException ( ExceptionMessageMap . getMessage ( "000005" ) + "  { variableName=[" + variableName + "] }" ) ; } for ( int i = 0 ; i < list . size ( ) ; i ++ ) { checkNullArgument ( list . get ( i ) , variableName ) ; } }
Checks a <code>List&lt;?&gt;</code> argument to make sure it is not null, has length > 0, and
none of its elements are null. If the <code>List&lt;?&gt;</code> or any contained instance is
null, a <code>NullPointerException</code> is thrown. If the <code>List&lt;?&gt;</code> or
any contained instance has length zero, an <code>IllegalArgumentException</code> is thrown.

@param list
The list to check.
@param variableName
The name of the variable being checked; for use in exception messages.
Checks a <code > List&lt ; ?&gt ; < / code > argument to make sure it is not null has length > 0 and none of its elements are null . If the <code > List&lt ; ?&gt ; < / code > or any contained instance is null a <code > NullPointerException< / code > is thrown . If the <code > List&lt ; ?&gt ; < / code > or any contained instance has length zero an <code > IllegalArgumentException< / code > is thrown .