code: public Object toNeo4JProperty(Object source)
      {
          if (source instanceof BigDecimal || source instanceof BigInteger)
          {
              return source.toString();
          }
          else if ((source instanceof Calendar) || (source instanceof GregorianCalendar))
          {
              return PropertyAccessorHelper.fromSourceToTargetClass(String.class, Date.class,
                      ((Calendar) source).getTime());
          }
          if (source instanceof Date)
          {
              Class<?> sourceClass = source.getClass();
              return PropertyAccessorHelper.fromSourceToTargetClass(String.class, sourceClass, source);
          }
          return source;
      }
docs: Converts a given field value to an object that is Neo4J compatible
  
  @param source
  @return