method Node.isSignaturedDeclarationimport { Node } from "https://dotland.deno.dev/x/fresh@1.1.1/src/dev/deps.ts"; isSignaturedDeclaration<T extends Node>(node: T | undefined): node is SignaturedDeclaration & SignaturedDeclarationExtensionType & TGets if the node is a SignaturedDeclaration. Gets if the node is a SignaturedDeclaration. Type ParametersT extends NodeParametersnode: T | undefined Node to check. Returnsnode is SignaturedDeclaration & SignaturedDeclarationExtensionType & T