class RuboCop::Cop::MultilineLiteralBraceCorrector

on the same line as the last contained elements, or a new line.
Autocorrection logic for the closing brace of a literal either

def call(corrector) 

def call(corrector)
  if closing_brace_on_same_line?(node)
    correct_same_line_brace(corrector)
  else
    # When a comment immediately before the closing brace gets in the
    # way of an easy correction, the offense is reported but not auto-
    # corrected. The user must handle the delicate decision of where to
    # put the comment.
    return if new_line_needed_before_closing_brace?(node)
    correct_next_line_brace(corrector)
  end
end

def correct_next_line_brace(corrector) 

def correct_next_line_brace(corrector)
  corrector.remove(
    range_with_surrounding_space(range: node.loc.end, side: :left)
  )
  corrector.insert_before(
    last_element_range_with_trailing_comma(node).end,
    node.loc.end.source
  )
end

def correct_same_line_brace(corrector) 

def correct_same_line_brace(corrector)
  corrector.insert_before(node.loc.end, "\n")
end

def initialize(node, processed_source) 

def initialize(node, processed_source)
  @node = node
  @processed_source = processed_source
end

def last_element_range_with_trailing_comma(node) 

def last_element_range_with_trailing_comma(node)
  trailing_comma_range = last_element_trailing_comma_range(node)
  if trailing_comma_range
    children(node).last.source_range.join(trailing_comma_range)
  else
    children(node).last.source_range
  end
end

def last_element_trailing_comma_range(node) 

def last_element_trailing_comma_range(node)
  range = range_with_surrounding_space(
    range: children(node).last.source_range,
    side: :right
  ).end.resize(1)
  range.source == ',' ? range : nil
end