How to use the apollo-language-server/lib/graphqlTypes.ChangeSeverity.WARNING function in apollo-language-server

const formatChange = (change: Change) => {
  let color = (x: string): string => x;
  if (change.severity === ChangeSeverity.FAILURE) {
    color = chalk.red;
  }

  if (change.severity === ChangeSeverity.WARNING) {
    color = chalk.yellow;
  }

  const changeDictionary: Record = {
    [ChangeSeverity.FAILURE]: "FAIL",
    [ChangeSeverity.WARNING]: "WARN",
    [ChangeSeverity.NOTICE]: "PASS"
  };

  return {
    severity: color(changeDictionary[change.severity]),
    code: color(change.code),
    description: color(change.description)
  };
};

const formatChange = (change: Change) => {
  let color = (x: string): string => x;
  if (change.severity === ChangeSeverity.FAILURE) {
    color = chalk.red;
  }

  if (change.severity === ChangeSeverity.WARNING) {
    color = chalk.yellow;
  }

  const changeDictionary: Record = {
    [ChangeSeverity.FAILURE]: "FAIL",
    [ChangeSeverity.WARNING]: "WARN",
    [ChangeSeverity.NOTICE]: "PASS"
  };

  return {
    severity: color(changeDictionary[change.severity]),
    code: color(change.code),
    description: color(change.description)
  };
};