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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 build_file_lines(self):
 """Like `target_lines`, the entire BUILD file's lines after dependency manipulation."""

    build_file_lines = self._build_file_source_lines[:]
    target_begin, target_end = self._target_interval
    build_file_lines[target_begin:target_end] = self.target_lines()
    return build_file_lines