code: public boolean remove(Object o) {
          int i = indexOf(o);
          if (i == -1)
              return false;
          else {
              removeAt(i);
              return true;
          }
      }
docs: Removes a single instance of the specified element from this queue,
  if it is present.  More formally, removes an element {@code e} such
  that {@code o.equals(e)}, if this queue contains one or more such
  elements.  Returns {@code true} if and only if this queue contained
  the specified element (or equivalently, if this queue changed as a
  result of the call).
  
  @param o element to be removed from this queue, if present
  @return {@code true} if this queue changed as a result of the call