In build.gradle.kts idea shows error: Null can not...

# gradle

[Jan Vomlel]

In build.gradle.kts idea shows error: Null can not be a value of a non-null type String,
But filter declaration in java allows nulls, in runtime it is working and in kt files it is compiled. Does exist some workarround, I dont wont red files in my project 🙂.
tasks.create<Copy>("test") {
filter {line -> /**some conditions**/ null}
}