let mutect ?(configuration=Mutect.Configuration.default) bam_pair =     let configuration_name = configuration.Mutect.Configuration.name in     let configuration_json = Mutect.Configuration.to_json configuration in     let make_target         ~run_with ~input ~result_prefix ?more_edges () =       match input with | Variant_caller.Somatic {normal; tumor} ->       Mutect.run         ~configuration         ?more_edges         ~run_with         ~normal ~tumor         ~result_prefix `Map_reduce in     somatic_variant_caller       {Variant_caller.name = "Mutect";        configuration_json;        configuration_name;        make_target;}       bam_pair