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: const_test.go
    path of file: ./repos/decimal
    
    the code of the file until where you have to start completion: package decimal

import "testing"

func TestConstApproximation(t *testing.T) {
	f
    
func TestConstApproximation(t *testing.T) {
	for _, testCase := range []struct {
		Const                 string
		Precision             int32
		ExpectedApproximation string
	}{
		{"2.3025850929940456840179914546", 0, "2"},
		{"2.3025850929940456840179914546", 1, "2.3"},
		{"2.3025850929940456840179914546", 3, "2.302"},
		{"2.3025850929940456840179914546", 5, "2.302585"},
		{"2.3025850929940456840179914546", 10, "2.302585092994045"},
		{"2.3025850929940456840179914546", 100, "2.3025850929940456840179914546"},
		{"2.3025850929940456840179914546", -1, "2"},
		{"2.3025850929940456840179914546", -5, "2"},
		{"3.14159265359", 0, "3"},
		{"3.14159265359", 1, "3.1"},
		{"3.14159265359", 2, "3.141"},
		{"3.14159265359", 4, "3.1415926"},
		{"3.14159265359", 13, "3.14159265359"},
	} {
		ca := newConstApproximation(testCase.Const)
		expected, _ := NewFromString(testCase.ExpectedApproximation)

		approximation := ca.withPrecision(testCase.Precision)

		if approximation.Cmp(expected) != 0 {
			t.Errorf("expected approximation %s, got %s - for const with %s precision %d", testCase.ExpectedApproximation, approximation.String(), testCase.Const, testCase.Precision)
		}
	}
}