FunctionDeclaration
constructor(modifiers: List<Node.Modifier>, lAngle: Node.Keyword.Less?, typeParameters: List<Node.TypeParameter>, rAngle: Node.Keyword.Greater?, receiverType: Node.Type?, name: Node.Expression.NameExpression?, lPar: Node.Keyword.LPar, parameters: List<Node.FunctionParameter>, rPar: Node.Keyword.RPar, returnType: Node.Type?, postModifiers: List<Node.PostModifier>, body: Node.Expression?, supplement: NodeSupplement = NodeSupplement())