code: public static DoubleBinding log(final ObservableDoubleValue a) {
          return createDoubleBinding(() -> Math.log(a.get()), a);
      }
docs: Binding for {@link java.lang.Math#log(double)}
  
  @param   a   a value
  @return  the value ln&nbsp;{@code a}, the natural logarithm of
  {@code a}.