code: public void removeAttribute(CBORObject label) throws CoseException {
          if (objProtected.ContainsKey(label)) {
              if (rgbProtected != null) throw new CoseException("Operation would modify integrity protected attributes");
              objProtected.Remove(label);
          }
          if (objUnprotected.ContainsKey(label)) objUnprotected.Remove(label);
          if (objDontSend.ContainsKey(label)) objDontSend.Remove(label);
      }
docs: Remove an attribute from the set of all attribute maps.
  
  @param label attribute to be removed
  @exception CoseException if integrity protection would be modified.