Email Attachments not working: RuntimeError #29

require 'adal'
require 'microsoft_graph'

# Code from example
username      = 'admin@tenant.onmicrosoft.com'
password      = 'xxxxxxxxxxxx'
client_id     = 'xxxxx-xxxx-xxx-xxxxxx-xxxxxxx'
client_secret = 'xxxXXXxxXXXxxxXXXxxXXXXXXXXxxxxxx='
tenant        = 'tenant.onmicrosoft.com'
user_cred     = ADAL::UserCredential.new(username, password)
client_cred   = ADAL::ClientCredential.new(client_id, client_secret)
context       = ADAL::AuthenticationContext.new(ADAL::Authority::WORLD_WIDE_AUTHORITY, tenant)
resource      = "https://graph.microsoft.com"
tokens        = context.acquire_token_for_user(resource, client_cred, user_cred)

# add the access token to the request header
callback = Proc.new { |r| r.headers["Authorization"] = "Bearer #{tokens.access_token}" }

graph = MicrosoftGraph.new(base_url: "https://graph.microsoft.com/v1.0",
                           cached_metadata_file: File.join(MicrosoftGraph::CACHED_METADATA_DIRECTORY, "metadata_v1.0.xml"),
                           api_version: '1.6', # Optional
                           &callback
)

me = graph.me # get the current user

# CUSTOM CODE
first_inbox_message = me.mail_folders.find('inbox').messages.first
first_inbox_message.attachments.first # => RuntimeError

    def coerce(value)
      value
    end