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: binaryTree.go
    path of file: ./repos/go-algorithms/binaryTree
    
    the code of the file until where you have to start completion: package binaryTree

type Comparable func(c1 interface{}, c2 interface{}) bool

type BinaryTree struct {
	node    interface{}
	left    *BinaryTree
	right   *BinaryTree
	less
    
func (tree *BinaryTree) Insert(value interface{}) {
	if tree.node == nil {
		tree.node = value
		tree.right = New(tree.lessFun)
		tree.left = New(tree.lessFun)
		return
	}
	if tree.lessFun(value, tree.node) {
		tree.left.Insert(value)
	} else {
		tree.right.Insert(value)
	}
}