You're seeing just the function put, go back to Mojito.Headers module for more information.
Link to this function

put(headers, name, value)

View Source


put(headers(), String.t(), String.t()) :: headers()

Puts the given header value under name, removing any values previously stored under name. The new header is placed at the end of the list.

Header names are matched case-insensitively, but case of name is preserved when adding the header.


iex> headers = [
...>   {"header1", "foo"},
...>   {"header2", "bar"},
...>   {"Header1", "baz"}
...> ]
iex> Mojito.Headers.put(headers, "HEADER1", "quux")
[{"header2", "bar"}, {"HEADER1", "quux"}]