testcases := map[string]struct {
		source       *core.FlexVolumeSource
		expectedErrs map[string]string
	}{
		"valid": {
			source:       &core.FlexVolumeSource{Driver: "foo"},
			expectedErrs: map[string]string{},
		},
		"valid with options": {
			source:       &core.FlexVolumeSource{Driver: "foo", Options: map[string]string{"foo": "bar"}},
			expectedErrs: map[string]string{},

            },
            "type": "array",
            "x-kubernetes-list-type": "atomic"
          }
        },
        "type": "object"
      },
      "io.k8s.api.core.v1.FlexVolumeSource": {
        "description": "FlexVolume represents a generic volume resource that is provisioned/attached using an exec based plugin.",
        "properties": {
          "driver": {
            "default": "",