code: @Nonnull
    public MimeType addParameter (@Nonnull final MimeTypeParameter aParameter)
    {
      ValueEnforcer.notNull (aParameter, "Parameter");
  
      m_aParameters.add (aParameter);
      return this;
    }
docs: Add a parameter.
  
  @param aParameter
  The parameter to be added. May not be <code>null</code>.
  @return this