Write the process Attach () function for Section 3.8.2. This function has two inputs, the body of a message and the Content-Type value. It returns a list of 2 elements. The first is called body and it contains the message body without its attachments. Be sure to consider the idiosyncratic cases of no attachments and a missing ending boundary string. The second element is a data frame called attach DF. This data frame has one row for each attachment in the message. There are 2 variables in this data frame, aLen and aType, which hold the number of lines and the MIME type of each attachment, respectively.