code: public static <T> List<T> asUnmodifiable(List<T> self) {
          return Collections.unmodifiableList(self);
      }
docs: Creates an unmodifiable view of a List.
  <pre class="groovyTestCase">
  def mutable = [1,2,3]
  def unmodifiable = mutable.asUnmodifiable()
  try {
  unmodifiable &lt;&lt; 4
  assert false
  } catch (UnsupportedOperationException) {
  assert true
  }
  mutable &lt;&lt; 4
  assert unmodifiable.size() == 4
  </pre>
  
  @param self a List
  @return an unmodifiable view of the List
  @see java.util.Collections#unmodifiableList(java.util.List)
  @since 2.5.0