BlockSandwich constructor

const BlockSandwich(
  1. StartBlock first,
  2. CitrusSyntaxList<DerivationCitrusSyntax> second,
  3. EndBlock third
)

ex:
{#for a in list}...{#for} {#true a == b}...{#true} {#false a == b}...{#false} {#fragment a}...{#fragment}

Implementation

const BlockSandwich(this.first, this.second, this.third);