module Avo::Concerns::ModelClassConstantized

def model_class=(value)

Cast the model class to a constantized version and memoize it like that 
def model_class=(value)
  @model_class = case value
  when Class
    value
  when String, Symbol
    value.to_s.safe_constantize
  else
    raise ArgumentError.new "Failed to find a proper model class for #{self}"
  end
end