indistinguishable vs like two peas in a pod

indistinguishable

noun

  • Any of a set of things that cannot be distinguished. 

adj

  • Not capable of being perceived or known. 

  • Not distinguishable; not capable of being perceived, known, or discriminated as separate and distinct 

like two peas in a pod

prep

  • Very similar; a couple made for each other. 

How often have the words indistinguishable and like two peas in a pod occurred in a corpus of books? (source: Google Ngram Viewer )