Define Custom Tasks 

Define a Task that runs tests in specific sub-projects 

Consider a hypothetical multi-build project with 3 subprojects. The following defines a task myTestTask that will run the test Task in specific subprojects core and tools but not client:

``` lazy val core = project.in(file(”./core”))

lazy val tools = project.in(file(”./tools”))

lazy val client = project.in(file(”./client”))

lazy val myTestTask = TaskKeyUnit

myTestTask <<= Seq( test in (core, Test) test in (tools, Test) ).dependOn ```