old_contents: class Workflow {
    constructor (client) {
      this.client = client
    }
  
    enroll (workflowId, email, cb) {
      return this.client._request({
        method: 'POST',
        path: `/automation/v2/workflows/${workflowId}/enrollments/contacts/${email}`,
      }, cb)
    }
  
    unenroll (workflowId, email, cb) {
      return this.client._request({
        method: 'DELETE',
        path: `/automation/v2/workflows/${workflowId}/enrollments/contacts/${email}`,
      }, cb)
    }
  }
  
  module.exports = Workflow
  
new_contents: class Workflow {
    constructor (client) {
      this.client = client
    }
  
    enroll (workflowId, email, cb) {
      return this.client._request({
        method: 'POST',
        path: `/automation/v2/workflows/${workflowId}/enrollments/contacts/${email}`
      }, cb)
    }
  
    unenroll (workflowId, email, cb) {
      return this.client._request({
        method: 'DELETE',
        path: `/automation/v2/workflows/${workflowId}/enrollments/contacts/${email}`
      }, cb)
    }
  
    current (contactId, cb) {
      return this.client._request({
        method: 'GET',
        path: `/automation/v2/workflows/enrollments/contacts/${contactId}`
      }, cb)
    }
  }
  
  module.exports = Workflow
  
subject: add current method