Additional interface to Fn.Presenter to control more precisely
garbage collection behavior of individual parameters. See
actual behavior of the interface.
Creates new function with given parameter names and provided body.
code - the body of the function. Can refer to variables named
names - names of parameters of the function - these will be
available when the code body executes
keepAlive - array of booleans describing for each parameter
whether it should be kept alive or not. Length of the array
must be the same as length of names array. The
array may be null to signal that all parameters
should be kept alive.