when i read doc:https://docs.gradle.org/current/javadoc/org/gradle/api/publish/maven/MavenPublication.html. i saw content blow.

A MavenPublication is the representation/configuration of how Gradle
should publish something in Maven format. You directly add a named
Maven publication the project’s publishing.publications container by
providing MavenPublication as the type.

 publishing {
   publications {
     myPublicationName(MavenPublication) {
       // Configure the publication here
     }
   }
 }

the part

 myPublicationName(MavenPublication) {
    // Configure the publication here
} 

syntax is very confusion. myPublicationName is not like a variable, also not like closure，also not like method, what should i understand in syntax.