You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: export.go
    path of file: ./repos/faas-netes/vendor/golang.org/x/tools/internal/event/core
    
    the code of the file until where you have to start completion: // Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LI
    
func ExportPair(ctx context.Context, begin, end Event) (context.Context, func()) {
	// get the global exporter and abort early if there is not one
	exporterPtr := (*Exporter)(atomic.LoadPointer(&exporter))
	if exporterPtr == nil {
		return ctx, func() {}
	}
	ctx = deliver(ctx, *exporterPtr, begin)
	return ctx, func() { deliver(ctx, *exporterPtr, end) }
}