FILE /variableAsFunctionCall.kt
  FUN public fun kotlin.String.k(): () -> kotlin.String
    BLOCK_BODY
      RETURN type=kotlin.Nothing from=k
        BLOCK type=() -> kotlin.String operator=LAMBDA
          FUN local final fun <anonymous>(): kotlin.String
            BLOCK_BODY
              RETURN type=kotlin.Nothing from=<anonymous>
                $RECEIVER of: k type=kotlin.String
          CALLABLE_REFERENCE local final fun <anonymous>(): kotlin.String type=() -> kotlin.String
  FUN public fun test1(/*0*/ f: () -> kotlin.Unit): kotlin.Unit
    BLOCK_BODY
      RETURN type=kotlin.Nothing from=test1
        CALL .invoke type=kotlin.Unit operator=INVOKE
          $this: GET_VAR f type=() -> kotlin.Unit operator=VARIABLE_AS_FUNCTION
  FUN public fun test2(/*0*/ f: kotlin.String.() -> kotlin.Unit): kotlin.Unit
    BLOCK_BODY
      RETURN type=kotlin.Nothing from=test2
        CALL .invoke type=kotlin.Unit operator=INVOKE
          $this: GET_VAR f type=kotlin.String.() -> kotlin.Unit operator=VARIABLE_AS_FUNCTION
          $receiver: CONST String type=kotlin.String value='hello'
  FUN public fun test3(): kotlin.String
    BLOCK_BODY
      RETURN type=kotlin.Nothing from=test3
        CALL .invoke type=kotlin.String operator=null
          $this: CALL .k type=() -> kotlin.String operator=null
            $receiver: CONST String type=kotlin.String value='hello'
  FUN public fun test4(/*0*/ ns: kotlin.String?): kotlin.String?
    BLOCK_BODY
      RETURN type=kotlin.Nothing from=test4
        WHEN type=kotlin.String? operator=SAFE_CALL
          if: CALL .EQEQ type=kotlin.Boolean operator=EQEQ
            arg0: GET_VAR ns type=kotlin.String? operator=null
            arg1: CONST Null type=kotlin.Nothing? value='null'
          then: CONST Null type=kotlin.Nothing? value='null'
          else: CALL .invoke type=kotlin.String operator=null
            $this: CALL .k type=() -> kotlin.String operator=null
              $this: GET_VAR ns type=kotlin.String? operator=null
