Issue #29 - Do not retrieve Environment variables just to get the command line

[oleg-nenashev]

It does not resolve the issue #29 , but it reduces its scope to API users, which actually do not
require Environment Variables. Unfortunately JENKINS-30782 is of such kind, because Jenkins process termination logic for builds relies on the environment variables.

OTOH, it is still a useful performance improvement

@reviewbybees

[ghost]

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[jglick]

Seems fine but if we are not solving JENKINS-30782, which is the bug affecting the main use case of this library IIUC, why are we doing it?

[oleg-nenashev]

@jglick

why are we doing it?

See the PR description

It does not resolve the issue #29 , but it reduces its scope to API users, which actually do not
require Environment Variables. Unfortunately JENKINS-30782 is of such kind, because Jenkins process termination logic for builds relies on the environment variables.

In Jenkins there are cases, when the code does not invoke WinProcess#getEnvironmentVariables (). So it will reduce the frequency of the issue and also improve the performance since the code won't be reading and parsing a big memory window. So it worth the new API method

[oleg-nenashev]

@reviewbybees done