即使我有导入ExecutionContex.global，也没有执行上下文

Question

我有导入import play.api.libs.concurrent.Execution.Implicits._

val lock1 = lock(tweet)
val lock2 = lock(tweet)
for {
  r1 <- lock1
  r2 <- lock2
} yield r1 -> r2

但是这个区块抱怨

Cannot find an implicit ExecutionContext, either require one yourself or import ExecutionContext.Implicits.global
[error]         r2 <- lock2
[error]            ^

Answer 1

import scala.concurrent.ExecutionContext.Implicits.global导入此工作正常。但我不知道为什么