You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: is_valid_test.go
    path of file: ./repos/tegola/basic
    
    the code of the file until where you have to start completion: package basic_test

import (
	"testing"

	"github.com/gdey/tbltest"
	"github.com/g
    
func TestIsValidPolygon(t *testing.T) {
	type testcase struct {
		desc     string
		polygon  basic.Polygon
		expected bool
	}
	tests := tbltest.Cases(
		testcase{
			desc: "Standard one line Polygon",
			polygon: basic.Polygon{
				basic.NewLine(4, 2, 6, 2, 8, 3, 8, 5, 7, 7, 5, 8, 3, 7, 2, 6, 2, 4),
			},
			expected: true,
		},
	)
	tests.Run(func(idx int, test testcase) {
		got := test.polygon.IsValid()
		if got != test.expected {
			t.Errorf("Test %v, expected %v got %v", idx, test.expected, got)
		}
	})
}