class Asciidoctor::AbstractBlock

def insert(i, block)

["foo", "bar", "baz"]
section.blocks
section.insert(1, 'bar')
section << 'baz'
section << 'foo'

section = Section.new

val = The content block to insert.
i - The Integer array index number.

list of blocks.
Public: Insert a content block at the specified index in this block's 
def insert(i, block)
  @blocks.insert(i, block)
end