code: public String getContainer(String property) {
          if (property == null) {
              return null;
          }
          if (JsonLdConsts.GRAPH.equals(property)) {
              return JsonLdConsts.SET;
          }
          if (!property.equals(JsonLdConsts.TYPE) && JsonLdUtils.isKeyword(property)) {
              return property;
          }
          final Map<String, Object> td = (Map<String, Object>) termDefinitions.get(property);
          if (td == null) {
              return null;
          }
          return (String) td.get(JsonLdConsts.CONTAINER);
      }
docs: Retrieve container mapping.
  
  @param property
  The Property to get a container mapping for.
  @return The container mapping if any, else null