code: protected boolean processSpecTopicInjectionErrors(final BuildData buildData, final BaseTopicWrapper<?> topic,
              final List<String> customInjectionErrors) {
          boolean valid = true;
  
          if (!customInjectionErrors.isEmpty()) {
              final String message = "Topic has referenced Topic/Level(s) " + CollectionUtilities.toSeperatedString(
                      customInjectionErrors) + " in a custom injection point that was not included this book.";
              if (buildData.getBuildOptions().getIgnoreMissingCustomInjections()) {
                  buildData.getErrorDatabase().addWarning(topic, ErrorType.INVALID_INJECTION, message);
              } else {
                  buildData.getErrorDatabase().addError(topic, ErrorType.INVALID_INJECTION, message);
                  valid = false;
              }
          }
  
          return valid;
      }
docs: Process the Injection Errors and add them to the Error Database.
  
  @param buildData             Information and data structures for the build.
  @param topic                 The topic that the errors occurred for.
  @param customInjectionErrors The List of Custom Injection Errors.
  @return True if no errors were processed or if the build is set to ignore missing injections, otherwise false.