okta_client = Oktakit.new(token: token, api_endpoint: api_endpoint)
response, http_status = okta_client.get_user('[email protected]')

# response
#-> {:errorCode=>"E0000007", :errorSummary=> "Not found: Resource not found: [email protected] (User)", :errorLink=>"E0000007", :errorId=>"oaeLRic8zbhTBiJ81eJnWTQUg", :errorCauses=>[]}
# response.class
#-> Sawyer::Resource

raise Oktakit::Error.from_response(response) unless http_status == 200
#->TypeError - exception object expected:
#-> ... trace ...

###
response = {:errorCode=>"E0000007", :errorSummary=> "Not found: Resource not found: [email protected] (User)", :errorLink=>"E0000007", :errorId=>"oaeLRic8zbhTBiJ81eJnWTQUg", :errorCauses=>[]}
###

# lib/oktakit/error.rb
module Oktakit
  # Custom error class for rescuing from all Okta errors
  class Error < StandardError
    # Returns the appropriate Oktakit::Error subclass based
    # on status and response message
    #
    # @param [Hash] response HTTP response
    # @return [Oktakit::Error]
    def self.from_response(response)
      status = response[:status].to_i # nil.to_i = 0
      if (klass = error(status)) # this block returns nil
        klass.new(response)
      end
    end
    ...
    
    def build_error_message
      return nil if @response.nil?

      message =  "#{@response[:method].to_s.upcase} " # no corresponding attribute
      message << redact_url(@response[:url].to_s) + ': ' # same here
      message << "#{@response[:status]} - " # and same here
      message << response_message.to_s unless response_message.nil?
      message
    end
    ...