code: @Nonnull
    public final BootstrapDateTimePicker setMode (@Nonnull final EBootstrap4DateTimePickerMode eMode)
    {
      ValueEnforcer.notNull (eMode, "Mode");
      m_eMode = eMode;
      return this;
    }
docs: Set the overall mode. By default DATE is selected. This implies, that the
  default format for the locale (as specified in the constructor is used). If
  you don't like the default, manually set the format but this should not be
  necessary.
  
  @param eMode
  Mode to use. May not be <code>null</code>.
  @return this for chaining
  @see #setFormat(String)