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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 get_src_names(gta):
 """Build and return a list of source name Parameters gta : `fermipy.GTAnalysis` The analysis object Returns ------- l : list Names of the source """

    o = []
    for s in gta.roi.sources:
        o += [s.name]
    return sorted(o)