compile error

The latest version can not compile, see:

> Task :compileJava
/opt/Downloads/pulsar-manager/src/main/java/org/apache/pulsar/manager/service/impl/BrokerStatsServiceImpl.java:132: error: cannot find symbol
if (StringUtils.isNotBlank(pulsarJwtToken)) {
^
symbol: variable pulsarJwtToken
location: class BrokerStatsServiceImpl
/opt/Downloads/pulsar-manager/src/main/java/org/apache/pulsar/manager/service/impl/BrokerStatsServiceImpl.java:132: error: cannot find symbol
if (StringUtils.isNotBlank(pulsarJwtToken)) {
^
symbol: variable StringUtils
location: class BrokerStatsServiceImpl
/opt/Downloads/pulsar-manager/src/main/java/org/apache/pulsar/manager/service/impl/BrokerStatsServiceImpl.java:133: error: cannot find symbol
header.put("Authorization", String.format("Bearer %s", pulsarJwtToken));
^
symbol: variable pulsarJwtToken
location: class BrokerStatsServiceImpl
/opt/Downloads/pulsar-manager/src/main/java/org/apache/pulsar/manager/service/impl/BrokerStatsServiceImpl.java:133: error: cannot find symbol
header.put("Authorization", String.format("Bearer %s", pulsarJwtToken));
^
symbol: variable header
location: class BrokerStatsServiceImpl
/opt/Downloads/pulsar-manager/src/main/java/org/apache/pulsar/manager/service/impl/BrokerStatsServiceImpl.java:139: error: cannot find symbol
String httpTestResult = HttpUtil.doGet( url + "/admin/v2/brokers/health", header);
^
symbol: variable header
location: class BrokerStatsServiceImpl
/opt/Downloads/pulsar-manager/src/main/java/org/apache/pulsar/manager/service/impl/BrokerStatsServiceImpl.java:139: error: cannot find symbol
String httpTestResult = HttpUtil.doGet( url + "/admin/v2/brokers/health", header);
^
symbol: variable HttpUtil
location: class BrokerStatsServiceImpl
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
6 errors

> Task :compileJava FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.