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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 read_sources_from_yaml_file(yamlfile):
 """ Open a yaml file and read all the new sources into a dictionary Parameters yaml : file name The input yaml file Returns ------- tab : `~astropy.table.Table` """

    f = open(yamlfile)
    dd = yaml.load(f)
    srcs = dd['sources']
    f.close()
    roi = ROIModel()
    roi.load_sources(srcs.values())
    return roi.create_table()