code: func (v *evalVisitor) VisitHash(node *ast.Hash) interface{} {
  	v.at(node)
  
  	result := make(map[string]interface{})
  
  	for _, pair := range node.Pairs {
  		if value := pair.Accept(v); value != nil {
  			result[pair.Key] = value
  		}
  	}
  
  	return result
  }
docs: // Miscellaneous
  // VisitHash implements corresponding Visitor interface method