Lambda ELB Multi Value header Input Payload

{
  "requestContext": {
    "elb": {
      "targetGroupArn": "arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/lambda-target/abcdefgh"
    }
  },
  "httpMethod": "GET",
  "path": "/",
  "multiValueQueryStringParameters": {
    "key": [
      "hello"
    ]
  },
  "multiValueHeaders": {
    "accept": [
      "*/*"
    ],
    "connection": [
      "keep-alive"
    ],
    "host": [
      "lambda-test-alb-1234567.us-east-1.elb.amazonaws.com"
    ],
    "user-agent": [
      "curl/7.54.0"
    ],
    "x-amzn-trace-id": [
      "Root=1-5c34e7d4-00ca239424b68028d4c56d68"
    ],
    "x-forwarded-for": [
      "72.21.198.67"
    ],
    "x-forwarded-port": [
      "80"
    ],
    "x-forwarded-proto": [
      "http"
    ],
    "x-imforwards": [
      "20"
    ],
    "x-myheader": [
      "123"
    ]
  },
  "body": "",
  "isBase64Encoded": false
}