class ActionController::Parameters

def []=(key, value)

Experimental RBS support (using type sampling data from the type_fusion project). 

def []=: (String key, String value) -> String

This signature was generated using 2 samples from 1 application.

when #permit is called.
Assigns a value to a given +key+. The given key may still get filtered out 
def []=(key, value)
  @parameters[key] = value
end