sdk/src/com/socialize/google/gdata/util/common/base/Preconditions.java
public static <T extends Iterable<?>> T checkContentsNotNull(T iterable) {
    if (containsOrIsNull(iterable)) {
      throw new NullPointerException();
    }
    return iterable;
  }
public static <T extends Iterable<?>> T checkContentsNotNull(T iterable) {
    if (containsOrIsNull(iterable)) {
      throw new NullPointerException();
    }
    return iterable;
  }
public static < T extends Iterable < ? > > T checkContentsNotNull ( T iterable ) { if ( containsOrIsNull ( iterable ) ) { throw new NullPointerException ( ) ; } return iterable ; }
Ensures that an {@code Iterable} object passed as a parameter to the
calling method is not null and contains no null elements.

@param iterable the iterable to check the contents of
@return the non-null {@code iterable} reference just validated
@throws NullPointerException if {@code iterable} is null or contains at
least one null element
Ensures that an { @code Iterable } object passed as a parameter to the calling method is not null and contains no null elements .