def read_attribute(name)
      field = fields[name.to_s]
      raw = read_raw_attribute(name)
      field ? field.demongoize(raw) : raw
    end
def read_attribute(name)
      field = fields[name.to_s]
      raw = read_raw_attribute(name)
      field ? field.demongoize(raw) : raw
    end
Read a value from the document attributes. If the value does not exist
 it will return nil.

 @example Read an attribute.
   person.read_attribute(:title)

 @example Read an attribute (alternate syntax.)
   person[:title]

 @param [ String, Symbol ] name The name of the attribute to get.

 @return [ Object ] The value of the attribute.

 @since 1.0.0