def build$\_$corpus$($texts$,$ lang$="$en$")$:

$"""$Corpus builder which returns a Corpus object processed on texts as language

specified by lang $($defaults to $"$en$")$:

Should perform all of the following pre$-$processing functions:

$-$ Lemmatize the tokens

$-$ Convert tokens to lowercase

$-$ Remove punctuation

$-$ Remove numbers

$-$ Remove tokens shorter than $2$ characters

$"""$

# Here, we just use the index of the text as the label for the corpus item

corpus $=$ Corpus$(\{$ i:r for i$,$ r in enumerate$($texts$)\},$ language$=$lang$)$

# TODO: Complete the implementation of this function and submit the

# $.$py download of this notebook as your assignment submission.