index.js
function getEnv(key) {
  return process.env[key.toLowerCase()] || process.env[key.toUpperCase()] || '';
}
function getEnv(key) {
  return process.env[key.toLowerCase()] || process.env[key.toUpperCase()] || '';
}
function getEnv ( key ) { return process . env [ key . toLowerCase ( ) ] || process . env [ key . toUpperCase ( ) ] || '' ; }
Get the value for an environment variable.

@param {string} key - The name of the environment variable.
@return {string} The value of the environment variable.
@private
Get the value for an environment variable .