code: def bam2fastq(self, input_bam, output_fastq,
                    output_fastq2=None, unpaired_fastq=None):
          
          self._ensure_folders(output_fastq, output_fastq2, unpaired_fastq)
          cmd = self.tools.java + " -Xmx" + self.pm.javamem
          cmd += " -jar " + self.tools.picard + " SamToFastq"
          cmd += " INPUT={0}".format(input_bam)
          cmd += " FASTQ={0}".format(output_fastq)
          if output_fastq2 is not None and unpaired_fastq is not None:
              cmd += " SECOND_END_FASTQ={0}".format(output_fastq2)
              cmd += " UNPAIRED_FASTQ={0}".format(unpaired_fastq)
          return cmd
docs: Create command to convert BAM(s) to FASTQ(s).
  
          :param str input_bam: Path to sequencing reads file to convert
          :param output_fastq: Path to FASTQ to write
          :param output_fastq2: Path to (R2) FASTQ to write
          :param unpaired_fastq: Path to unpaired FASTQ to write
          :return str: Command to convert BAM(s) to FASTQ(s)