code: private void init(CmsResource resource, CmsObject cms, String property) {
  
          try {
              cms.readPropertyDefinition(property);
              CmsProperty prop = cms.readPropertyObject(resource, property, false);
  
              if (prop == CmsProperty.getNullProperty()) {
                  m_propertyValue = "";
              } else {
                  m_propertyValue = prop.getValue();
              }
          } catch (CmsDbEntryNotFoundException dbe) {
              // property are not configured
              throw new CmsIllegalArgumentException(
                  Messages.get().container(Messages.ERR_COLLECTOR_PARAM_PROPERTY_NOT_FOUND_1, property));
          } catch (CmsException cmse) {
              // something's gone wrong...
              cmse.printStackTrace();
          }
      }
docs: Initializes the comparator key based on the member variables.<p>
  
  @param resource the resource to use
  @param cms the current OpenCms user contxt
  @param property the name of the sort property (case sensitive)