class Asciidoctor::Extensions::Preprocessor

Preprocessors must extend Asciidoctor::Extensions::Preprocessor.
to the same Reader or a reference to a new one.
Preprocessor modifies the Array as necessary and either returns a reference
to the process method of an instance of each registered Preprocessor. The
Asciidoctor passes a reference to the Reader and a copy of the lines Array
from each line and leaves behind a line-feed character (i.e., “n”).
lines and normalizes them. The normalize process strips trailing whitespace
Prior to invoking the preprocessor, Asciidoctor splits the source text into
before parsing begins.
Public: Preprocessors are run after the source text is split into lines and

def process reader, lines

Each subclass of Preprocessor should override this method.

needed, then returns the Reader or a reference to a new one.
Public: Accepts the Reader and an Array of lines, modifies them as 
def process reader, lines
  reader
end