class ActiveStorage::Transformers::Transformer

backed by ImageProcessing, a common interface for MiniMagick and ruby-vips
* ActiveStorage::Transformers::ImageProcessingTransformer:
The following concrete subclasses are included in Active Storage:
A Transformer applies a set of transformations to an image.
= Active Storage Transformers Transformer

def initialize(transformations) 

def initialize(transformations)
  @transformations = transformations
end

def process(file, format:) # :doc:

:doc:
All subclasses implement this method.
Returns an open Tempfile containing a transformed image in the given +format+. 
def process(file, format:) # :doc:
  raise NotImplementedError
end

def transform(file, format:)

the output tempfile after yielding to the given block. Returns the result of the block.
specified +format+. Yields an open Tempfile containing the target image. Closes and unlinks
Applies the transformations to the source image in +file+, producing a target image in the 
def transform(file, format:)
  output = process(file, format: format)
  begin
    yield output
  ensure
    output.close!
  end
end