<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def spp_call_peaks( self, treatment_bam, control_bam, treatment_name, control_name, output_dir, broad, cpus, qvalue=None):
 """ Build command for R script to call peaks with SPP. :param str treatment_bam: Path to file with data for treatment sample. :param str control_bam: Path to file with data for control sample. :param str treatment_name: Name for the treatment sample. :param str control_name: Name for the control sample. :param str output_dir: Path to folder for output. :param str | bool broad: Whether to specify broad peak calling mode. :param int cpus: Number of cores the script may use. :param float qvalue: FDR, as decimal value :return str: Command to run. """

        broad = "TRUE" if broad else "FALSE"
        cmd = self.tools.Rscript + " `which spp_peak_calling.R` {0} {1} {2} {3} {4} {5} {6}".format(
            treatment_bam, control_bam, treatment_name, control_name, broad, cpus, output_dir
        )
        if qvalue is not None:
            cmd += " {}".format(qvalue)
        return cmd