AbstractCoroutineContextKey
constructor(baseKey: CoroutineContext.Key<B>, safeCast: (element: CoroutineContext.Element) -> E?)(source)
Parameters
B
base class of a polymorphic element
baseKey
an instance of base key
E
element type associated with the current key
safeCast
a function that can safely cast abstract CoroutineContext.Element to the concrete E type and return the element if it is a subtype of E or null otherwise.