}
LocalDate endDate = DateConstraint.evaluate(executionContext, endDateString);
final boolean includeEnd = HistoricalTimeSeriesFunctionUtils.parseBoolean(desiredValue.getConstraint(HistoricalTimeSeriesFunctionUtils.INCLUDE_END_PROPERTY));
final String surfaceName = desiredValue.getConstraint(ValuePropertyNames.SURFACE);
final VolatilitySurfaceDefinition<Object, Object> definition = getSurfaceDefinition(target, surfaceName, definitionSource);
final VolatilitySurfaceSpecification specification = getSurfaceSpecification(target, surfaceName, specificationSource);
final SurfaceInstrumentProvider<Object, Object> provider = (SurfaceInstrumentProvider<Object, Object>) specification.getSurfaceInstrumentProvider();
final HistoricalTimeSeriesBundle bundle = new HistoricalTimeSeriesBundle();
for (final Object x : definition.getXs()) {
for (final Object y : definition.getYs()) {
ExternalId id = provider.getInstrument(x, y, endDate);
if (id.getScheme().equals(ExternalSchemes.BLOOMBERG_TICKER_WEAK)) {