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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 _format_executable(lines, element, spacer=""):
 """Performs formatting specific to a Subroutine or Function code element for relevant docstrings. """

    rlines = []
    rlines.append(element.signature)
    _format_summary(rlines, element)

    rlines.append("")
    rlines.append("PARAMETERS")
    for p in element.ordered_parameters:
        _format_value_element(rlines, p)

    rlines.append("")
    _format_generic(rlines, element, ["summary"])

    #Subroutines can have embedded types and functions which need to be handled.
    if len(element.types) > 0:
        rlines.append("\nEMBEDDED TYPES")
        for key, value in list(element.types.items()):
            _format_type(rlines, value, "  ")

    if len(element.executables) > 0:
        rlines.append("\nEMBEDDED EXECUTABLES")
        for key, value in list(element.executables.items()):
            _format_executable(rlines, value, "  ")

    lines.extend([spacer + l for l in rlines])