#NEWLINE# @ extensionmethod ( Observable ) #NEWLINE# def start_with( self , * args , **kw ) : #NEWLINE# #INDENT# 'Prepends a sequence of values to an observable sequence with an\n    optional scheduler and an argument list of values to prepend.\n\n    1 - source.start_with(1, 2, 3)\n    2 - source.start_with(Scheduler.timeout, 1, 2, 3)\n\n    Returns the source sequence prepended with the specified values.\n    ' #NEWLINE# scheduler = kw . get ( 'scheduler' ) #NEWLINE# if ( ( not scheduler ) and isinstance ( args [ 0 ] , Scheduler ) ) : #NEWLINE# #INDENT# scheduler = args [ 0 ] #NEWLINE# args = args [ 1 : ] #NEWLINE# #UNINDENT# else : #NEWLINE# #INDENT# scheduler = immediate_scheduler #NEWLINE# #UNINDENT# sequence = [ Observable . from_ ( args , scheduler ) , self ] #NEWLINE# return Observable . concat ( sequence )