code: public static DoubleBinding atan2(final ObservableDoubleValue y, final ObservableDoubleValue x) {
          return createDoubleBinding(() -> Math.atan2(y.get(), x.get()), y, x);
      }
docs: Binding for {@link java.lang.Math#atan2(double, double)}
  
  @param   y   the ordinate coordinate
  @param   x   the abscissa coordinate
  @return  the <i>theta</i> component of the point
  (<i>r</i>,&nbsp;<i>theta</i>)
  in polar coordinates that corresponds to the point
  (<i>x</i>,&nbsp;<i>y</i>) in Cartesian coordinates.