/// <reference types="node" />
import { Transform, TransformCallback, TransformOptions } from 'stream';
import { Field } from '../interfaces';
export interface ExtendContractTransformOptions extends TransformOptions {
    fields: Field[];
    refDate?: Date;
}
export declare class ExtendContractTransform extends Transform {
    private opts;
    private vb;
    private dg;
    constructor(opts?: ExtendContractTransformOptions);
    _transform(chunk: Buffer, encoding: string, callback: TransformCallback): void;
    _flush(callback: TransformCallback): void;
    private updateField;
}