docs: public String getParameterName() {
          ParameterNameDiscoverer discoverer = this.parameterNameDiscoverer;
          if (discoverer != null) {
              String[] parameterNames = (this.method != null ? discoverer.getParameterNames(this.method)
                      : discoverer.getParameterNames(this.constructor));
              if (parameterNames != null) {
                  this.parameterName = parameterNames[this.parameterIndex];
              }
              this.parameterNameDiscoverer = null;
          }
          return this.parameterName;
      }