<dependency>
  <groupId>checkstyle</groupId>
  <artifactId>checkstyle-optional</artifactId>
  <version>4.1</version>
</dependency>

implementation 'checkstyle:checkstyle-optional:4.1'

implementation("checkstyle:checkstyle-optional:4.1")

libraryDependencies += "checkstyle" % "checkstyle-optional" % "4.1"

@Grapes(
  @Grab(group='checkstyle', module='checkstyle-optional', version='4.1')
)

<dependency org="checkstyle" name="checkstyle-optional" rev="4.1" />

[checkstyle/checkstyle-optional "4.1"]

'checkstyle:checkstyle-optional:jar:4.1'