Functions
activate_writer_version(name, ver)
activate_writer_version
调试工具，用于切换“默认”写入器实现
active_writer_version(name)
active_writer_version
load()
load
Modules
ampl
baron_writer
cpxlp
gams_writer
lp_writer
mps
nl_writer
parameterized_standard_form
standard_form