```ruby
# Copyright 2011-2017, The Trustees of Indiana University and Northwestern
#   University.  Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software distributed
#   under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
#   CONDITIONS OF ANY KIND, either express or implied. See the License for the
#   specific language governing permissions and limitations under the License.
# ---  END LICENSE_HEADER BLOCK  ---

module PlayerHelper
  def is_mejs_2?
    !is_mejs_4?
  end

  def is_mejs_4?
    session['mejs_version'] == 4 || params['mejs4'] === 'true'
  end
end
```

Use MEJS4 unless told to do otherwise
user
```ruby
# Copyright 2011-2017, The Trustees of Indiana University and Northwestern
#   University.  Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software distributed
#   under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
#   CONDITIONS OF ANY KIND, either express or implied. See the License for the
#   specific language governing permissions and limitations under the License.
# ---  END LICENSE_HEADER BLOCK  ---

module PlayerHelper
  def is_mejs_2?
    session['mejs_version'] == 2 || params['mejs4'] === 'false'
  end

  def is_mejs_4?
    !is_mejs_2?
  end
end
```
assistant