Standardise way to get children blocks of containers

src/building_blocks.jl

@@ -28,10 +28,21 @@ abstract type GradientBlock <: BuildingBlock end
 
 """
 Parent type for all types combining one or more pulses/gradients.
+
+Required methods:
+- [`get_children_blocks`](@ref): return all the [`BuildingBlock`](@ref) objects includes in this container with their indices.
 """
 abstract type ContainerBlock <: BuildingBlock end
 
 
+"""
+    get_children_blocks(container)
+
+Return all the [`BuildingBlock`](@ref) objects includes in this container with their indices.
+"""
+function get_children_blocks end
+
+
 """
     start_time(container, args...)
 
@@ -72,6 +83,11 @@ function scanner_constraints!(model::Model, building_block::BuildingBlock, scann
             @constraint model func(building_block) <= func(scanner)
         end
     end
+    if building_block isa ContainerBlock
+        for (_, child_block) in get_children_blocks(building_block)
+            scanner_constraints!(model, child_block, scanner)
+        end
+    end
 end
 
 """

src/containers/sequences.jl

@@ -2,7 +2,7 @@ module Sequences
 import JuMP: Model, @constraint
 import ...BuildSequences: @global_model_constructor
 import ...Variables: variables, start_time, duration, VariableType, get_free_variable, TR
-import ...BuildingBlocks: BuildingBlock, ContainerBlock, to_block, add_scanner_constraints!
+import ...BuildingBlocks: BuildingBlock, ContainerBlock, to_block, get_children_blocks
 
 """
     Sequence(building_blocks...)
@@ -14,7 +14,7 @@ struct Sequence <: ContainerBlock
     model :: Model
     blocks :: Vector{<:BuildingBlock}
     TR :: VariableType
-    function Sequence(model::Model, blocks::Vector; TR=nothing)
+    function Sequence(model::Model, blocks::AbstractVector; TR=nothing)
         seq = new(
             model,
             to_block.(blocks),
@@ -31,6 +31,7 @@ Sequence(model::Model, blocks...; TR=nothing) = Sequence(model, [blocks...]; TR=
 
 Base.length(seq::Sequence) = length(seq.blocks)
 Base.getindex(seq::Sequence, index) = seq.blocks[index]
+get_children_blocks(seq::Sequence) = enumerate(seq.blocks)
 
 """
     start_time(sequence::Sequence, index::Integer, args...)