How to use the ember-cli-page-object.is function in ember-cli-page-object

save: clickable('.done'),
      hasError: isVisible('.validation-error-message'),
    },
    supplemental: {
      scope: '.sessionsupplemental',
      isActive: is(':checked', 'input'),
      click: clickable('.toggle-yesno'),
    },
    specialAttire: {
      scope: '.sessionspecialattire',
      isActive: is(':checked', 'input'),
      click: clickable('.toggle-yesno'),
    },
    specialEquipment: {
      scope: '.sessionspecialequipment',
      isActive: is(':checked', 'input'),
      click: clickable('.toggle-yesno'),
    },
    attendanceRequired: {
      scope: '.sessionattendancerequired',
      isActive: is(':checked', 'input'),
      click: clickable('.toggle-yesno'),
    },
    toggleIlm: clickable('.toggle-yesno', { scope: '.independentlearningcontrol' }),
  },

  leadershipCollapsed,
  leadershipExpanded: {
    scope: '[data-test-session-leadership-expanded]',
    title: text('.title'),
    manage: clickable('.actions button'),
    save: clickable('.actions button.bigadd'),

rendersAccountNumberField: isVisible('[name=account-number]'),
  rendersRoutingNumberField: isVisible('[name=routing-number]'),
  rendersSubmitButton:isVisible('button'),

  accountLast4Text: text('.bank-account__account p'),
  bankNameText: text('.bank-account__bank-name p'),
  routingNumberText: text('.bank-account__routing p'),

  accountNumber: fillable('[name=account-number]'),
  routingNumber: fillable('[name=routing-number]'),

  clickSubmit: clickable('button'),

  accountNumberFieldIsDisabled: is(':disabled', '[name=account-number]'),
  routingNumberFieldIsDisabled: is(':disabled', '[name=routing-number]'),
  submitButtonIsDisabled: is(':disabled', 'button')
};

fillIn: fillable(),
    value: value()
  },

  cardYear: {
    scope: 'select.year',
    selectOption: selectable(),
    value: value()
  },

  clickSubmit: clickable('button.submit-card'),
  clickCancel: clickable('div.cancel-add-card a'),

  submitButtonIsVisible: isVisible('button.submit-card'),
  submitButtonText: text('button.submit-card'),
  submitDisabled: is(':disabled', 'button')
};

import { clickable, fillable, is, isVisible } from 'ember-cli-page-object';

export default {
  scope: '.personal-id-number',

  clickSubmit: clickable('button'),

  legalEntityPersonalIdNumber: fillable('input[type=text]'),
  legalEntityPersonalIdNumberFieldIsDisabled: is(':disabled', 'input[type=text]'),

  renderslegalEntityPersonalIdNumberField: isVisible('input[type=text]'),
  rendersSubmitButton: isVisible('button'),

  submitButtonIsDisabled: is(':disabled', 'button')
};