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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def validate_bam(self, input_bam):
 """ Wrapper for Picard's ValidateSamFile. :param str input_bam: Path to file to validate. :return str: Command to run for the validation. """

        cmd = self.tools.java + " -Xmx" + self.pm.javamem
        cmd += " -jar " + self.tools.picard + " ValidateSamFile"
        cmd += " INPUT=" + input_bam
        return cmd