Comet parameter: activation_method
         
         - This parameter specifies which scan types are searched.
         
- If "ALL" is specified, no filtering based on the activation method
         is applied.
         
- If any other allowed entry is chosen, only spectra with activation
         method matching the specified entry are searched.
         
- This parameter is valid only for mzXML, mzML and mz5 input.
         
- Allowed values are: ALL, CID, ECD, ETD, PQD, HCD, IRMPD
         
- The default value is "ALL" if this parameter is missing.
         
Example:
         
activation_method = ALL
         
activation_method = CID
         
activation_method = ETD
         
activation_method = HCD