Mongo.UnorderedBulk.replace_one

You're seeing just the function replace_one, go back to Mongo.UnorderedBulk module for more information.
Link to this function

replace_one(bulk, filter, replacement, opts \\ [])

View Source

Specs

replace_one(t(), BSON.document(), BSON.document(), Keyword.t()) :: t()

Appends a replace operation with :multi = false.

Example:

Mongo.UnorderedBulk.replace_one(bulk, %{name: "Waldo"}, %{name: "Greta", kind: "dog"})
%Mongo.UnorderedBulk{
coll: "bulk",
deletes: [],
inserts: [],
updates: [{%{name: "Waldo"}, %{kind: "dog", name: "Greta"}, [multi: false]}]
}