code: public void putEntry(String entityName, Class<?> clazz, boolean overwrite) throws Siren4JException {
          if (StringUtils.isBlank(entityName)) {
              throw new IllegalArgumentException("entityName cannot be null or empty.");
          }
          if (clazz == null) {
              throw new IllegalArgumentException("clazz cannot be null.");
          }
          if (!overwrite && containsEntityEntry(entityName)) {
              String newline = "\n";
              StringBuilder msg = new StringBuilder("Attempted to add a resource with duplicate name to the registry: ");
              msg.append(newline);
              msg.append("Entity Name: ");
              msg.append(entityName);
              msg.append(newline);
              msg.append("Existing class: ");
              msg.append(getClassByEntityName(entityName).getName());
              msg.append(newline);
              msg.append("Other class: ");
              msg.append(clazz.getName());
              LOG.error(msg.toString());
              throw new Siren4JException(msg.toString());
          }
          LOG.info("Found Siren4J resource: [name: "
                  + entityName + "] [class: " + clazz.getName() + "]");
          entries.put(entityName, clazz);
  
      }
docs: /* (non-Javadoc)
  @see com.google.code.siren4j.converter.ResourceRegistry#putEntry(java.lang.String, java.lang.Class, boolean)