function makeOperationSnippet(operationName) {
  return [
    "${1:" + operationName + "}:",
    "  summary: ${2}",
    "  description: ${2}",
    "  responses:",
    "    ${3:200:}",
    "      description: ${4:OK}",
    "${6}"
  ].join("\n")
}
Makes an HTTP operation snippet's content based on operation name

@param {string} operationName - the HTTP verb

@return {string} - the snippet content for that operation