add

Adds a new document with an automatically generated id and data (a map of field values).

Completes once the write is acknowledged, as on Android (addDocumentWithData returns the reference before that).

Adds a new document with an automatically generated id and data (a map of field values).

Adds a new document with an automatically generated id and data (a map of field values).

Adds a new document with an automatically generated id and data (a map of field values).