code: func CheckPathConflicts(c *Compiler, exists func([]string) (bool, error)) Errors {
  	var errs Errors
  
  	root := c.RuleTree.Child(DefaultRootDocument.Value)
  	if root == nil {
  		return nil
  	}
  
  	for _, node := range root.Children {
  		errs = append(errs, checkDocumentConflicts(node, exists, nil)...)
  	}
  
  	return errs
  }
docs: // CheckPathConflicts returns a set of errors indicating paths that
  // are in conflict with the result of the provided callable.