function buildParams (identifier, instanceState) {
  var params = {}

  if (instanceState) {
    params.Filters = [
      {
        Name: 'instance-state-name',
        Values: [instanceState]
      }
    ]
  }

  if (isInstanceId(identifier)) {
    params.InstanceIds = [identifier]
    return params
  }

  params.Filters = params.Filters || []

  params.Filters.push({
    Name: 'tag:Name',
    Values: [identifier]
  })

  return params
}
function buildParams (identifier, instanceState) {
  var params = {}

  if (instanceState) {
    params.Filters = [
      {
        Name: 'instance-state-name',
        Values: [instanceState]
      }
    ]
  }

  if (isInstanceId(identifier)) {
    params.InstanceIds = [identifier]
    return params
  }

  params.Filters = params.Filters || []

  params.Filters.push({
    Name: 'tag:Name',
    Values: [identifier]
  })

  return params
}
function buildParams ( identifier , instanceState ) { var params = { } if ( instanceState ) { params . Filters = [ { Name : 'instance-state-name' , Values : [ instanceState ] } ] } if ( isInstanceId ( identifier ) ) { params . InstanceIds = [ identifier ] return params } params . Filters = params . Filters || [ ] params . Filters . push ( { Name : 'tag:Name' , Values : [ identifier ] } ) return params }
Builds the correct set of params depending on whether or not the
identifier is an instanceId or a name.

@param {state} instanceState
@param {string} identifier
@returns {object} params for the ec2.describeInstances call.
Builds the correct set of params depending on whether or not the identifier is an instanceId or a name .