TestObject.scala

object TestObject extends TestTraitClass {

    val immutableVariable: String = "Hello Immutable"
    var mutableVariable: String = "Hello Mutable"
    
    def getImmutable(): String = immutableVariable
    
    def getMutable(): String = {
        mutableVariable
    }
    
    def setMutable(m: String) = {
        mutableVariable = m
    }
}

TestTraitClass.scala

trait TestTraitClass {
    def getImmutable(): String
    def getMutable(): String
    def setMutable(m:String)
    def implementedMethod(): String = "This is a string"
}