method Node.prototype.getFirstChildimport { Node } from "https://dotland.deno.dev/x/fresh@1.1.5/src/dev/deps.ts"; getFirstChild<T extends Node>(condition?: (node: Node) => node is T): T | undefinedGets the first child by a condition. getFirstChild(condition?: (node: Node) => boolean): Node | undefinedGets the first child by a condition. Gets the first child by a condition. Type ParametersT extends NodeParametersoptionalcondition: (node: Node) => node is T Condition. ReturnsT | undefinedGets the first child by a condition. Parametersoptionalcondition: (node: Node) => boolean Condition. ReturnsNode | undefined