code: @Override
      public Class<?> getProxyClass() {
          if (proxyClass != null) {
              return proxyClass;
          }
          try {
              if (StringUtils.isNotBlank(interfaceId)) {
                  this.proxyClass = ClassUtils.forName(interfaceId);
                  if (!proxyClass.isInterface()) {
                      throw ExceptionUtils.buildRuntime("service.interfaceId",
                          interfaceId, "interfaceId must set interface class, not implement class");
                  }
              } else {
                  throw ExceptionUtils.buildRuntime("service.interfaceId",
                      "null", "interfaceId must be not null");
              }
          } catch (SofaRpcRuntimeException e) {
              throw e;
          } catch (Throwable e) {
              throw new SofaRpcRuntimeException(e.getMessage(), e);
          }
          return proxyClass;
      }
docs: Gets proxy class.
  
  @return the proxyClass