code: func (ns *Namespace) Append(args ...interface{}) (interface{}, error) {
  	if len(args) < 2 {
  		return nil, errors.New("need at least 2 arguments to append")
  	}
  
  	to := args[len(args)-1]
  	from := args[:len(args)-1]
  
  	return collections.Append(to, from...)
  
  }
docs: // Append appends the arguments up to the last one to the slice in the last argument.
  // This construct allows template constructs like this:
  //     {{ $pages = $pages | append $p2 $p1 }}
  // Note that with 2 arguments where both are slices of the same type,
  // the first slice will be appended to the second:
  //     {{ $pages = $pages | append .Site.RegularPages }}