public String buildExtensionField(String extensionKey, String field) {StringBuilder builder = new StringBuilder(field);builder.append(this.extensionFieldDelimiter);builder.append(extensionKey);return escapeExtensionField(builder.toString());}
public virtual string BuildExtensionField(string extensionKey, string field){StringBuilder builder = new StringBuilder(field);builder.Append(this.extensionFieldDelimiter);builder.Append(extensionKey);return EscapeExtensionField(builder.ToString());}