def stringify_headers headers
headers.inject({}) do |result, (key, value)|
if key.is_a? Symbol
key = key.to_s.split(/_/).map { |w| w.capitalize }.join('-')
end
if 'CONTENT-TYPE' == key.upcase
target_value = value.to_s
result[key] = MIME::Types.type_for_extension target_value
elsif 'ACCEPT' == key.upcase
if value.is_a? Array
target_values = value
else
target_values = value.to_s.split ','
end
result[key] = target_values.map { |ext| MIME::Types.type_for_extension(ext.to_s.strip) }.join(', ')
else
result[key] = value.to_s
end
result
end
end