code: public static DoubleBinding expm1(final ObservableDoubleValue x) {
          return createDoubleBinding(() -> Math.expm1(x.get()), x);
      }
docs: Binding for {@link java.lang.Math#expm1(double)}
  
  @param   x   the exponent to raise <i>e</i> to in the computation of
  <i>e</i><sup>{@code x}</sup>&nbsp;-1.
  @return  the value <i>e</i><sup>{@code x}</sup>&nbsp;-&nbsp;1.