Cannot import kotlin.test.Test with gradle

I use (don't care about versions, I use platform to manage versions):

testCompile("org.jetbrains.kotlin:kotlin-test-testng")
testCompile("org.jetbrains.kotlin:kotlin-test")
testCompile("org.jetbrains.kotlin:kotlin-test-common")

But cannot import kotlin.test.Test:

import kotlin.test.Test

Test shows red in IDEA, means not found, Why? something I ignored?