Object.Expressionlet assignment: Parser_env.env => Flow_ast.Expression.t(Loc.t, Loc.t);let assignment_cover: Parser_env.env => Parser_common.pattern_cover;let conditional: Parser_env.env => Flow_ast.Expression.t(Loc.t, Loc.t);let is_assignable_lhs: Flow_ast.Expression.t(Loc.t, Loc.t) => bool;let left_hand_side: Parser_env.env => Flow_ast.Expression.t(Loc.t, Loc.t);let number: Parser_env.env => Token.number_type => string => float;let sequence: 
  Parser_env.env =>
  start_loc:Loc.t =>
  list(Flow_ast.Expression.t(Loc.t, Loc.t)) =>
  Flow_ast.Expression.t(Loc.t, Loc.t);