@Override
 public boolean equals(final Object o) {
   if (o == null) {
     return false;
   }
   if (!(o instanceof VolatilitySurfaceData)) {
     return false;
   }
   final VolatilitySurfaceData<?, ?> other = (VolatilitySurfaceData<?, ?>) o;
   return getDefinitionName().equals(other.getDefinitionName())
       && getSpecificationName().equals(other.getSpecificationName())
       && getTarget().equals(other.getTarget())
       && Arrays.equals(getXs(), other.getXs())
       && Arrays.equals(getYs(), other.getYs())
       && getXLabel().equals(other.getXLabel())
       && getYLabel().equals(other.getYLabel())
       && _values.equals(other._values);
 }