code: func (s *ArraySchema) MarshalJSON() ([]byte, error) {
  	return json.Marshal(struct {
  		Type  string `json:"type,omitempty"`
  		Items Schema `json:"items,omitempty"`
  	}{
  		Type:  "array",
  		Items: s.Items,
  	})
  }
docs: // MarshalJSON serializes the given schema as JSON.