Returns an async function which can NOT be executed simultaneously with the same arguments.
Any attempt to call again while a prior call with same args is executing will return the first promise.
Once a promise completes, then a new call with same args could occur.
Returns an async function which can NOT be executed simultaneously with the same arguments. Any attempt to call again while a prior call with same args is executing will return the first promise. Once a promise completes, then a new call with same args could occur.