[update] setting input param of type 'map' to undefined results in error

[vsnig]

const MyEntity = new Entity({
  ..., 
  attributes: { 
    ...,
    someAttr: 'string', 
    myMap: 'map'
}

await MyEntity.update({ someAttr: 'foo'}) // works fine
await MyEntity.update({ someAttr: 'foo', myMap: undefined}) // TypeError: Cannot read property '$set' of undefined

Error stack trace is pointing here

Is it expected behaviour? In my opinion, non-required property set to 'undefined' should be treated same as missing property and not result in error.