code: private boolean isFiltered(HeaderType<?> headerType)
  	{
  		for (HeaderType<?> type : mFilteredHeaderTypes)
  		{
  			if (type.equals(headerType))
  			{
  				return true;
  			}
  		}
  		return false;
  	}
docs: Returns whether a Header of the given type may be in this set or if it's been removed explicitly.
  
  @param headerType
  @return