class RuboCop::Cop::Rails::IndexWith

}]
[1, 2, 3].map { |el| [el, foo(el)] }.to_h
[1, 2, 3].to_h { |el| [el, foo(el)] }
[1, 2, 3].each_with_object({}) { |el, h| h = foo(el) }
# bad
@example
Rails provides the ‘index_with` method for this purpose.
an enumerable into a hash where the keys are the original elements.
`map { … }.to_h`, and `Hash[map { … }]` that are transforming
Looks for uses of `each_with_object({}) { … }`,